[clang] [libclang/python] Add typing annotations for the Type class (PR #140378)

[Jannick Kremer via cfe-commits]

DeinAlptraum wrote:

@Endilll 
> Our error handling story is bad and inconsistent, but that's out of scope of this PR

What sort of improvements would you like to see?


Also possibly related, reminder that #102410 is still open

https://github.com/llvm/llvm-project/pull/140378