mercurial: Rename from_disk module to the main and official loader
Note: This impacts production:
- the task must be renamed in the scheduler backend
- the worker configuration must be changed to drop the no longer used names
- the docker/kubernetes configuration must be adapted as well
I'll attend to those once i've landed/packaged this.
Related to #3612 (closed) Depends on !83 (closed)
Test Plan
tox
Migrated from D6361 (view on Phabricator)