Remove catalogue version 5.0 from CTA and move backwards compatible changes to catalogue version 4.6

Make cta-admin --json sq show the mount policy with highest priority and the
mount policy with lowest request age for each queue

New catalogue table and respective cta-admin diskinstance and
cta-admin diskinstancespace commands

Activity Mount Rules associate a Mount Policy to an activity regex.

When recalling a file, the users can specify an activity (i.e. by using
filepath?activity=x). If specified, this activity will be used to select
a matching activity mount rule, if one exists. If more than one Activity
Mount Rule matches the activity, the one with highest retrieve priority
will be chosen.

Acitivity Mount Rules take precedence over Requester Mount Rules.

Restoring deleted files implies restoring them in the eos namespace and
in the cta catalogue. The command has no atomicity guarantees, a file
may be restored in the eos namespace but the restoring in the cta
catalogue may fail.

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.

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

CTA frontend now logs the following configuration values at startup

* cta.catalogue.numberofconnections
* cta.objectstore.backendpath
* cta.schedulerdb.numberofthreads
* cta.archivefile.max_size_gb
* cta.repack.repack_buffer_url
* cta.ns.config

* Add clientHost to the cta::common::dataStructures::SecurityIdentity struct, defining the machine the cta command was submitted from
* cta::comon::dataStructures::SecurityIdentity::host now represents the frontend machine the commands were executed on, and is set by the server