[clang] [clang-tools-extra] [clang-tidy] Add new check: `readability-redundant-typename` (PR #161574)

[Victor Chernyakin via cfe-commits]

localspook wrote:

Successfully [ran the check over stdexec](https://github.com/localspook/stdexec/commit/b958de862b710dc901e4030e80fe31f517f21d4e) (well, successfully after fixing the two bugs it found)

https://github.com/llvm/llvm-project/pull/161574