Decide the fate of random beacon agent

[5A11]

Decide the fate of random_beacon_feed agent.

Stargateworld does not have random beacon functionality. So this agent does not work with Stargateworld.
Beaconworld net may also be phased out soon, so keeping the current beaconworld setup means this agent would stop working.

Check whether random beacon functionality is going to be available on a future version of Stargateworld. If so, keep the current beaconworld setup and switch to Stargateworld when it supports random beacon. If this functionality will never be supported anymore, we might have to retire this agent (as it will not run on any network).

Related comment:
#2613 (comment)