Teams CLI interface
Created by: eseliger
This implements a CLI interface for managing/ingesting teams into Sourcegraph.
This still requires https://github.com/sourcegraph/sourcegraph/pull/47143 on the backend but otherwise is functional, so opening up for review to get some feedback on it and I will make sure to re-test once that PR landed. (Also removing team members is not yet implemented in the backend so that also has to wait for a bit to test)
Closes https://github.com/sourcegraph/sourcegraph/issues/48228
Test plan
Manually verified things work with an ingestion script I'm still working on to shove over teams from GitHub into our instance.