Support REST convention with pluralized entities in mode with IgnoreOperationId=true

[GennadyGS]

Problem is in confusing method names, generated for routes with parameters (due to name collisions).

For example, following provider methods are generated for given routes:
/areas -> GetAreas(...)
/areas/{id} -> GetAreas1(...)

Desired behavior:
/areas -> GetAreas(...)
/areas/{id} -> GetArea(...)

The solution is to singularize route segments, followed by parameters.

Existing unit tests are fixed, integration tests are remained broken (issues not related to PR in both cases). New tests are not created, because of existing issues and because I did not find simple way to test my changes. I am ready to elaborate on tests in case of principal approval of idea.

As for new branch openapi and nuget beta I was not able to test it, because it does not work for me (at least in LinqPad). However I noticed, that logic, related to my changes, basically remained the same.

Thanks.

[sergey-tihon]

Thank you the idea and implementation, @GennadyGS!
Agree, that it naming approach is better than initial one.
Since code changes a lot in master, I ported you code and merged in both TPs.
Changes released in 0.10.0-beta10

[GennadyGS]

Thanks for merging!