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

The DiskReadTask task issues DiskFile::size to validate the file size.
As Xroot protocol always return the StatInfo on open and as tape files
are immutable (even if not files are not locked, this calling stat and
then read doesn't guarantee that file is not changed), there are no
needs to enforce the xroot client to ignore stat cache.

Changed the freeSpaceQueryURL Regex in order to prepare for the parsing of the EOS Space name in DiskSystem

Added a check for the repack just add copies workflow that verify that two archive routes does not point to the same tapepool

Remove the repack buffer if the repack expansion indicates that no Retrieve is necessary
Corrected the XrootDirectory::exist() method

Started the strcutures needed for sleeping a retrieve queue.

The disk system is now vetoed for the duration of a mount if we fail to reserve free space.