Keep track of disk systems associated with each queue.
For use case https://gitlab.cern.ch/cta/operations/-/issues/564
In order to be able to monitor the retrieve disk systems (before mounting the tape), we need to keep track, per queue, of the number of requests per disk system.
To do this we need to update the objectstore schema to add a map of diskSystemName -> count and increment/decrement the respective entry when pushing/popping the queue.
This information then needs to be displayed in cta-admin sq