Storage: Fix snapshot_get_latest implementation
While working on the Subversion loader, I noticed that the snapshot_get_latest method from the Storage class was not returning the latest snapshot to date for an origin but instead the first created one.
That diff fixes the underlying database query in order for the method to honor its semantics.
Test Plan
Test data have been updated accordingly to capture the fixed issue.
Migrated from D419 (view on Phabricator)