Implement Oxc.scope to rename top-level bindings

[marcoroth]

Oxc.scope renames everything a file declared at the top level, so two copies of the same script on one page never collide. Every reference to a renamed name follows it, and a name the file did not declare is left alone.

result = Oxc.scope(source, scope: "1a2b3c4d")

result.code
#=> "let count_1a2b3c4d = 0;\nfunction bump_1a2b3c4d() { count_1a2b3c4d += 1; render(label) }\n"

result.renamed
#=> {"bump" => "bump_1a2b3c4d", "count" => "count_1a2b3c4d"}

[marcoroth]

Superseded by the visitor and mutation visitor in #3 and #4. Scoping is now expressible as a Ruby codemod over MutationVisitor plus symbols, which preserves formatting and comments and needs neither rename_symbol nor Codegen::with_scoping.