[Native] Remove old protos and related files
Summary:
Remove old protobuf files now that
all references have been updated.
https://linear.app/comm/issue/ENG-1231
Depends on D5045 D5044 D5043 D5042 D4998 D5041 D4995 D4994 D4993 D4992
Test Plan: CI gates pass
Reviewers: atul, abosh, varun, max
Reviewed By: atul
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D5046