Flushing stdout and sending ERROR messages to stdout as redirection would be applied to stdbuff command

Fixed.

Moreover, the PL/SQL code for the CTA catalogue is temporarily
moved out of the catalogue folder as it requires some schema
changes that are still work in progress in a dev branch. Until
then, all migration code is evolved in the migration/ folder.

Moved disk-operations-related code into the new "disk" directory

Removed helgrind error by removing a linkage in the tapeserver/castor/tape/tapeserver/file/CMakeLists.txt file

Refactored the async deletion of repack subrequests files via XRootD (used the xroot's async deletion)
Deleted the folder containing the repack subrequests files (Local file + XRootD)

The folder containing the files need now to be removed

Added the creation of the directory corresponding to the vid of the tape to repack (xroot + local file system)

References:
https://gitlab.cern.ch/cta/CTA/issues/479 (on the CTA side)
Jira: CASTOR-5526: support the migration to CTA (on the CASTOR side)

The latter won't be updated further, all required code will
be committed here and gitlab tickets will be updated accordingly.

Fixes race condition: for text stream responses, guarantees that
header is printed before the stream data.

workaround for jq when output is not a tty as seen [here](https://github.com/stedolan/jq/issues/1110#issuecomment-193504718)

Added a display of the state of the tape before and after each repack

Simple repack on CI

Corrected cta-admin af ls command so that it fills the superseded vid and superseded columns in the result