[clang] [libclang/python] Expose Rewriter to the python binding (PR #77269)

[Vlad Serebrennikov via cfe-commits]

https://github.com/Endilll commented:

Looks good overall.
It's good that you wrote your own tests, but it would also be nice to mirror tests in `clang/unittests/libclang/LibclangTest.cpp` which test the same API. This way we can identify issues in binding layer itself (when C++ tests pass, but Python tests don't, or vise versa,)

https://github.com/llvm/llvm-project/pull/77269