[services/commtest] Tunnelbroker - Adding deviceID validation check function

Summary:
This diff introduces a function that makes a call to the Tunnelbroker (get signature API) with the deviceID in the wrong format.
In this case, we are making sure that the Tunnelbroker returns an error on the wrong format deviceID provided.
This function is called during the test in D5931.

Linear task: ENG-1657

Test Plan: The commtest app is successfully built and the tests are successfully passed in the following D5931 where the function is used.

Reviewers: jon, bartek

Reviewed By: jon

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D5929