[terraform] Add Tunnelbroker
Summary:
Terraform configuration from Tunnelbroker.
RabbitMQ docs: terraform resource, AWS docs.
The service is mostly copy-paste from other services
Test Plan: Created a Docker image from the stack and tested deployment on staging.
Reviewers: kamil, michal, varun, jon
Reviewed By: michal
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D9165