new ESP service method for reporting Activity Information for containerized HPCC

The method is for new ECLWatch Activity page. The method should return a list of the queue targets with active (running or queuing) workunits associated with them, and some state information.

The primary view/info for the activity page is to see the targets (the hthor, thor and roxie queues), and the state of the workunits that have been submitted to them.
Each target queue, has several queues associated with it. e.g. a thor has an compile queue (eclccserver), a workflow queue (eclagent), and a thor agent queue (that actually spins up thor instances).
Knowing the state of a workunit, as it transitions through these queues/other states is useful, it's secondary information, that should probably be accessed or linked to under the main list of active workunits under each target.

See the comments in: https://github.com/hpcc-systems/HPCC-Platform/pull/14440