Do not scroll record blob provider by default when triggering Full GC

When triggering a Full GC on a repository, we iterate over each blob provider to scroll its blobs. However, the Records blob provider (if any) should not be scrolled by default.

There should not be any orphaned blobs associated with a record document because they are deleted immediately whenever a record document is removed. (see DefaultBlobDispatcher#notifyBeforeRemove)

We can still introduce a nuxeo.conf property to exceptionally enable the Full GC on record blob providers.