Add support for `include_prefix` and / or `strip_include_prefix` for `rb_library` rules

`cc_libraries` have a concept of being able to manipulate the prefix of the libraries, e.g.:

https://bazel.build/reference/be/c-cpp#cc_library.include_prefix
https://bazel.build/reference/be/c-cpp#cc_library.strip_include_prefix

It would be great if `rb_library` supported similar capabilities.

Without it, we find that Bazel Ruby scripts have to do awkward load path manipulation that we don't think non-Bazel ruby users would normally have to worry about.

Context: https://github.com/protocolbuffers/protobuf/pull/19808#discussion_r1983709783