[APINotes] Upstream APINotesOptions

This upstreams more of the Clang API Notes functionality that is
currently implemented in the Apple fork:
https://github.com/apple/llvm-project/tree/next/clang/lib/APINotes

This adds the first compiler options related to API Notes to the
upstream Clang: `-iapinotes-modules` and `-fapinotes-swift-version=`.
However, this does not add the `-fapinotes` flag that enables API Notes,
since the feature is not fully functional yet.