Adding a deprecated API version annotation to deprecated fields and enum values in proto files.
This is part of the work on adding minor/patch versioning work.
Risk Level: Low (adding annotation to existing protos).
Testing: Added and modified tests for the tooling (in tools/testdata).
Signed-off-by: Adi Suissa-Peleg <adip@google.com>
Mirrored from https://github.com/envoyproxy/envoy @ 5a8bfa20dc3c85ecb61826d122696ecaa75dffa0