Cleanup the RPC Implementations section
Cleanup the RPC Implementations section

Remove dead links and update the ones that were moved.

Use https when possible.

Isolate inactive projects (not updated in the last few years) in a subsection.

release notes: no

google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf