[clang-tools-extra] [clang-tidy] Added check 'misc-override-with-different-visibility' (PR #140086)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat approved this pull request.

This commit still LGTM and it would be nice to get it merged.

@PiotrZSL @EugeneZelenko @vbvictor Are you satisfied with the current state of the commit? Do you have any concerns that are not answered yet?

https://github.com/llvm/llvm-project/pull/140086