Consider adding a backward compatibility checker for gRPC APIs

[alexhamel]

Proposal includes:
• Add a new 'break' or 'compat' target in each gRPC API's Makefile
• Have the new target invoke the 'buf breaking' tool (https://buf.build/docs/breaking/overview)
• Have a rolling check against the 'main' branch of the repository or check against a previous release/git tag
• Do not enforce the 'compat' check for now. It could easily be enforced later on. Either at build time or in CI/CD.

[sandersms]

We are moving to Buf v2 currently and running the buf action CI which included the breaking check. The plan is to enable the buf breaking at some point in the CI/CD