Merge links into nodes: Merge nodes on links if there are no node injection sensors

[mgovers]

This is the actual enablement of merging nodes on links (a.k.a. merging links into nodes).

As described in #1550, a dual code path is chosen:

• If there are no node injection sensors:
  • Follow the v2 behavior: run a multi-scale calculation:
    • Links are modeled to have infinite admittance at the macro-scale, and link power/current flows are distributed in a micro-scale calculation after obtaining the macro-scale results.
    • Details are explained in Merge links into nodes: Documentation #1553 .
• Otherwise:
  • Follow the original behavior ( <= v1.13.166): Links are modeled to have a finite admittance.
    • This behavior maintains backwards compatibility while we are still on v1. Node injection sensors are deprecated in [DEPRECATION] Deprecating node injection power sensor #1334 and will be removed in v2.

Documentation is in #1553 .

This reverts commit e743f9c.

Fixes #35

[mgovers]

Benchmark run vs v1.13.163; looks OK

[figueroa1395]

We only merge after #1583 has been merged into #1550 and then once #1550 has been merged into main and released.

We want two explicit releases with the differences so we can pinpoint to an exact, very contained version, if anything was to go wrong at any point in time.

[mgovers]

This PR now depends on both #1550 and #1566 (for the right reasons). All LGTM, but main needs to be merged into this branch after those PRs are merged.

The base branch was changed.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[figueroa1395]

#1566 and then #1550 merged correctly and there aren't any conflicts nor changes in this PR. Hence this is good to go.