[Nix] Add script to start/stop tunnelbroker services

Summary:
Tunnelbroker development services have significant
resources costs compared to mariadb or redis. Thus the starting
and stopping of such services shouldn't be done unilaterally with
every 'nix develop'.

First introduce paradigm with rabbitmq.

https://linear.app/comm/issue/ENG-1696

Test Plan:
On macOS (intel or m1)

nix develop

comm-dev services stop # ensure rabbitmq is stopped

pgrep beam.smp # should be empty

comm-dev services start # should emit some rabbitmq info
comm-dev services start # should be no-op

pgrep beam.smp # should show a PID

comm-dev services stop # optional, cleanup rabbitmq

Reviewers: atul, varun, max, ashoat

Reviewed By: max, ashoat

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D5758