Move targets and packages from build-go to config-go

@filbranden This should help with building things not using the build-go script and doing it by hand.  This should be the last of the 'brains' in build-go.sh
Actually, I would suggest not touching build/* in this PR and leaving this for a follow up PR. @jbeda previously volunteered to converge this, so maybe if we could get your code into hack/ then he could take over and reuse it in build/ ?

I think it's easier treating these two as separate issues since then we can make sure they're thoroughly tested and that in case something goes wrong we can roll them back independently.