Support User Project option for StorageControl API
Attempting to run the samples for disabling and getting status on a requester pays enabled object (#3291) reveal that we should have a way to provide an option (like the C++ library does) to set the x-goog-user-project header for storage control requests.
Related to #3189 and they should likely use the same design.
Should we add user project to RequestOptions, RequestOptionsBuilder ?
https://github.com/googleapis/google-cloud-rust/blob/e40933ae224e4f7db2c0aadd6bb1f70216958e18/src/gax/src/options.rs#L43
and handle it in the gaxi clients
https://github.com/googleapis/google-cloud-rust/blob/e40933ae224e4f7db2c0aadd6bb1f70216958e18/src/gax-internal/src/grpc.rs#L215
https://github.com/googleapis/google-cloud-rust/blob/e40933ae224e4f7db2c0aadd6bb1f70216958e18/src/gax-internal/src/http.rs#L96
Should we add user project to RequestOptions, RequestOptionsBuilder ?
I agree that seems like the right place for it.