[clang] [cindex] Add support for calling getFullyQualifiedName to the Python binding. (PR #135420)

[Brian Cody via cfe-commits]

epistax wrote:

> @epistax I just realized you don't have perms to merge, right? If this is ready from your side, shall I merge?

That's right. Yep this is ready from my side. I'd appreciate it if you merged! Thanks

https://github.com/llvm/llvm-project/pull/135420