This patch enables the creation of a share from snapshot
specifying another pool or backend. In the scheduler, a
new filter and weigher were implemented in order to consider
this operation if the backend supports it. Also, a new
field called 'progress' was added in the share and share
instance. The 'progress' field indicates the status
of the operation create share from snapshot (in percentage).
Finally, a new periodic task was added in order to constantly
check the share status.
Partially-implements: bp create-share-from-snapshot-in-another-pool-or-backend
Co-authored-by: carloss <firstname.lastname@example.org>
Co-authored-by: dviroel <email@example.com>