[clang-tools-extra] Add check 'modernize-use-enum-class' (PR #138282)

[Baranov Victor via cfe-commits]

https://github.com/vbvictor commented:

Overall, good niche check that may find its user, however some work need to be done.

Move this check to `cppcoreguidelines-` section, you can use `clang-tools-extra\clang-tidy\rename_check.py` for that.
`modernize-` checks are used for smooth codebase improvements, and they should not (hopefully) break any existing code in any way (e.g. no changes to behavior, no new compiler errors). In your case, automatically converting `enum` to `enum class` will probably create hundreds compiler errors for big codebases, and that does not align with `modernize` philosophy.

https://github.com/llvm/llvm-project/pull/138282