[clang-tools-extra] [clang-tidy] Add `modernize-use-bit-cast` check (PR #189962)

[Daniil Dudkin via cfe-commits]

unterumarmung wrote:

> I think the check should also support `sizeof(float)`, not just `sizeof(var)`. You can compare the underlying canonical types of the arg and the sizeof arg type.

This was actually working but not tested. I added the tests and reflected it in the docs.

https://github.com/llvm/llvm-project/pull/189962