Parameterize the tag system and the threshold level

**What it's the actual situation on ARA ?**
Currently the tag system is managed in a conf file. (@severity-sanity-check / @severity-high / @severity-medium)

It would be useful to be able to manage our tags directly from the ARA interface.

This way each project could choose its own name at the tag level.

Also for the threshold management part, being able to parameterize the thresholds directly from the ARA interface could be very interesting.

Start by locating the configuration that defines the current tags and thresholds, then trace the ARA interface where project settings are managed. Done means each project can choose its own tag names and adjust threshold values directly from the interface, with those settings replacing the fixed configuration.

Written by the indexing model from the issue text.