Analyze hash collisions

Currently we store contents. When hitting a hash collision, we do not reference the next content colliding with a previously already stored ones.

All in all, this task serves the purpose of being sure those exists. And what can we do to avoid losing information.

Migrated from T2332 (view on Phabricator)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information