Run restoreLinkedEntities when needed

We currently process all remaining tasks and restore all of their linked entities before processing any of them, which is a waste of time & resources in many case.

However we need to:

Beware of the retry counter which will be incremented in case we postpone a task (for instance if the associated FS factory isn't present) while it probably shouldn't
Ensure we ignore restoration of linked entities for new tasks, as it will probably be called, but there will be nothing to restore.

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