feat(codecs): add support for protobuf encoding (#18598)

* feat(codecs): add support for protobuf encoding

* rename descriptor_set_path to desc_file

* fix spelling errors

* describe encode_message

* factor out common test code

* move protobuf test data to one directory

* create common protobuf module

* add map encoding and test

* add enum encoding and test

* add timestamp encoding and test

* fix spelling again

* assert -> assert_eq

* remove simple comments

* enums are not case-sensitive

* add round trip test

* spelling (maybe?)

* fix clippy errors