Add RMQ claim and cleanup

[j3parker]

Having the LE put its RMQ endpoint inside the access token allows the Caliper gateway to be independent of that config. So we won't need one per-BDP stack (decrease costs, annoyance etc.)

Long term solution involves having an actual service discovery solution, so the CG would query the RMQ endpoint for a particular tenant rather than having a global config.

The downside to this approach is that the LE gets to "aim" the CG at whatever it pleases. However the threat model for the CG very much assumes a trustworthy LE at this point.

Other work outside this PR required to fully implement:

• LE needs to set this claim (exists in a branch)
• Need to whitelist this claim type for the LE in the auth service (involves adding to a static const array somewhere)
• CG needs to pull this value out

[j3parker]

Not going with this solution yet because of how we manage RMQ deployments.

[j3parker]

Actually I'm going to keep the other commits, one sec.

[j3parker]

Ah ok needs a separate PR because Github doesn't like that the branch was deleted, restored and the force pushed to :)