Remove all the code associated to the activity weight fair share
scheduling feature:

- Remove catalogue functions interacting with the ACTIVITY_WEIGHTS table
- Remove code related to activity weights from the scheduler.
- Deprecate and mark as optional objectstore schema fields for activity
  weights (shcema should be backwards and forwards compatible).
- Store only activity information in the drive state. In the catalogue
  methods, default the weight values to 1.0 (avoids having to perform a
backwards incompatible catalogue upgrade)

And suppresses two false positive warnings in templated classes

Add youngestjobcreationtime to archive and retrieve queues in the
objectstore. The change is backwards compatible, as the new field is
optional and with a default value of 0.

The field is updated everywhere in the code where oldestjobcreationtime
is also updated. The value is printed per queue using cta-admin sq.

Using a dump tool and jq, the objectstore can be easily explored.
This README.md presents the methods.

add declaration of the fully specialised getElementSummary() method
for archive queues

During the July datachallenge the archiveJobTransferForUser queue for the r_atlas_test_datachallenge
tapepool became full of ArchiveJobs whose bytes field became zero after popped from the queue.
This caused the tape servers to pop ~5TB of work from the queue. To prevent this from happening in
the future, instead of summing the sizes of the individual elements popped from the queue, we now
subtract them from the total size popped. This way, if there are popped jobs that have incorrectly
set their bytes field to zero, the algorithm will consume less data than expected, not exponencially
more

Remove the looping through the retrieve queue jobs while holding the global lock in OStoreDB::fetchMountInfo.
This was done when a tape was disabled, since we mount disabled tapes if they have pending retrieve requests.
Instead we now mount the tape if the queue object info as in the mount policy map a mount policy whose name
starts with "repack".

With this change, cta-admin now forces repacks added with the --disabledtape to have a mount policy
prefixed with repack (without the --disabledtape flag, the mount policy can have any name)

Also Removed the criteria that a disabled/broken tape is mounted if the queue is filled with deleted
retrieved jobs. Eventually the maxrequestage for the queue will expire, the tape will be mounted
and the queue flushed