Generated the json files of non repacked files, self repacked files and repacked files for further jq querying
Added a script repack_generate_report.sh that will be executed at the end of each repack_systemtest

Added unit test to test it
Added a Repack Request expansion time limit (if the expansion last more than this time limit, it will be requeued)
Added jq to the buildtree

switching from single threaded gzip to as many cores as possible using xz. We should generate smaller log artifacts than before and get them faster.

This reverts commit 14cc088c.

Added Repack timeout
Added documentation for the usage of that script
Used full name parameters on admin_cta commands

Added repack_systemtest.sh that allows to execute a repack on a specified VID with only cta-admin and eos commands

Created a repack_systemtest_wrapper.sh script to allow to execute the repack_systemtest.sh in the CI
Adapted the simple_repack.sh script so that it uses the repack_systemtest.sh script

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

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