[tunnelbroker] Recover AMQP before publishing messages

Summary:
Similiar to D13607 (recover when session is closing) and D13606 (consumer is broken).
Before publishing, check channel state and recover if needed. Eventually propagate error if both fail.

Depends on D13609

Test Plan: Tested on staging with the rest of the stack

Reviewers: kamil, will, varun

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D13611