[clang-tools-extra] [clang-tidy] Added check 'misc-visibility-change-to-virtual-function' (PR #140086)

[Balázs Kéri via cfe-commits]

balazske wrote:

I like the names `misc-inconsistent-virtual-function-visibility` and `misc-override-with-different-visibility`.

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