Fix bugs to ensure unique parameter names

[wing328]

• Fix bugs to ensure unique parameter names
• Add tests

Related: #5963

Credit: @thiagoarrais for creating the test spec.

cc @OpenAPITools/generator-core-team

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[thiagoarrais]

Quick review: as I understand, this deduplicates parameter names by adding a numerical suffix. While this is useful for stopping compilers from complaining, I think it may be confusing for the programmers using generated clients.

Would you be interested in a PR that namespaces the parameteres to their request location (cp.paramName == "queryId", cp2.paramName == "formId", etc.) when needed? This would work much like #5963, but not limited to an specific generator.

[wing328]

@thiagoarrais thanks for the review. Also thanks for the PR to start the work on this. Much appreciated.

Would you be interested in a PR that namespaces the parameteres to their request location (cp.paramName == "queryId", cp2.paramName == "formId", etc.

General speaking we totally welcome enhancements. For this particular case, the PR may need to target 6.0x branch as it's a breaking changes without fallback given that the duplicated parameter names will have a better naming using the request location.

Please open a PR for 6.0.x and we'll review and get it merged accordingly.