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

[Jannick Kremer via cfe-commits]

https://github.com/DeinAlptraum commented:

Re Python: A few minor nits, otherwise this looks good to me.

@Endilll can you review the C++ side?

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