[PWGLF] Add GenLevelStudy and Code simplification in hStrangeCorrelation.cxx

[kcui1]

1, Add final stage to check the reconstruction efficiency
2, Code simplification
3, Add GenLevelStudy

[github-actions]

O2 linter results: ❌ 12 errors, ⚠️ 2 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 45fd347 at 2026-08-22 13:50:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 3 errors and 55 warnings.'
Found 3 errors and 55 warnings.
++ [[ 3 -gt 0 ]]
++ cat /sw/BUILD/cf7394ebfa3a62cc684b39ce4784685740291b94/O2Physics-code-check/errors.txt
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:95:8: error: constructor does not initialize these fields: ccdb, pdgDB [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:767:5: error: Variable 'radius' with floating point type 'double' should not be used as a loop counter [clang-analyzer-security.FloatLoopCounter,-warnings-as-errors]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:1143:5: error: Variable 'r' with floating point type 'double' should not be used as a loop counter [clang-analyzer-security.FloatLoopCounter,-warnings-as-errors]
++ [[ 55 -gt 0 ]]
++ cat /sw/BUILD/cf7394ebfa3a62cc684b39ce4784685740291b94/O2Physics-code-check/warnings.txt
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:1573:75: warning: use designated initializer list to initialize 'PairLossPairKey' [modernize-use-designated-initializers]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3129:9: warning: the 'empty' method should be used to check for emptiness instead of comparing to an empty object [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3307:9: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3537:9: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3574:9: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3729:9: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3814:11: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3871:13: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3930:13: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:3980:11: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4083:13: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4113:9: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4340:15: warning: boolean expression can be simplified by DeMorgan's theorem [readability-simplify-boolean-expr]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4342:41: warning: use 'contains' to check for membership [readability-container-contains]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4379:36: warning: use 'contains' to check for membership [readability-container-contains]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4431:15: warning: boolean expression can be simplified by DeMorgan's theorem [readability-simplify-boolean-expr]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4433:30: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4447:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4458:28: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4532:13: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4536:31: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4650:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4651:30: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4652:30: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4675:32: warning: use 'contains' to check for membership [readability-container-contains]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4728:61: warning: use designated initializer list to initialize 'PairLossFinalRecord' [modernize-use-designated-initializers]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4729:32: warning: use designated initializer list to initialize 'PairLossPairKey' [modernize-use-designated-initializers]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4844:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4858:11: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4892:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4940:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4941:30: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4942:30: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:4996:28: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:5009:26: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:5020:28: warning: redundant explicit casting to the same type 'int64_t' (aka 'long') as the sub-expression, remove this casting [readability-redundant-casting]
PWGLF/Tasks/Strangeness/hStrangeCorrelation.cxx:5494:34: warning: use 'contains' to check for membership [readability-container-contains]
[0 more errors; see full log]

Full log here.