[Tunnelbroker] Remove existing tunnelbroker tables

Summary:
Remove stale tables from tf configuration. To avoid
data collision with existing data, use new naming.

Part of: https://linear.app/comm/issue/ENG-3823

Test Plan:

# verify that terraform works
cd services/terraftorm
./run.sh

Reviewers: bartek, varun

Reviewed By: bartek

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7717