feat(internal/gapicgen): support adding context to regen #3174
Now all regen PRs will include a block that mentions all of the
Now all regen PRs will include a block that mentions all of the changes that happened in googleapis/googleapis that caused the files to be generated. This information will eventually be fed into our automated releases via release-please. There these changes will be parsed out to add extra context to our release PRs and changelogs. No longer will we have to have a vague message about many auto-generated changes. - Adds context to regen PRs. - Refactored generators so every method does not need so many parameters. - Updated goolge/protobuf to its new migrated repo protocolbuffers/protobuf. - Added some extra logging to the build. - Only run protoc on dirs that have changes.