Automate Makefile

[amckinney]

The current Makefile setup isn't complete - new users need a variety of tools already installed in order to use it, and running make won't automatically install the dependencies you need. This is prone to version mismatch bugs on different developer machines, and causes a lot of headache to get started with our GitHub action development (this also applies to buf-{lint,breaking,push}-action).

Additionally, we should verify that make build doesn't produce a diff in CI, similar to what we do for make generate in our other repositories.

These are tasks that should have been done from the very beginning, but were left as an afterthought and repeatedly forgotten about.