[clang-tools-extra] [clang-tidy] Add new check readability-trailing-comma (PR #173669)

[Baranov Victor via cfe-commits]

vbvictor wrote:

Actually, this check now has very little knowledge about AST/semantics, so I think It may be reasonable to implement it as an `clang-format` option (fortunately, all test cases are already present).

You may postpone review now, I either mark it as ready for review if I fail in `clang-format`  or close the PR if eventually land in `clang-format`

https://github.com/llvm/llvm-project/pull/173669