Pull individual entities

• see remote content entities: See only created, updated or deleted entities (new revision)
• pull only selected entities

InternalReplicator: ok, needs patch from #2817495-4: Provide way(s) to examine "pending" changes in a Workspace
CouchdbReplicator: ok, needs patches from : #2817495-4: Provide way(s) to examine "pending" changes in a Workspace, #2842379-2: Examine pending changes, https://github.com/FlorentTorregrosa/couchdb-replicator/commit/edce6f49a...

Improvements/ideas:

• see diff with current entities: Make a clear indication if the entity has been updated, created or deleted
• Improve the pull form page:
  • Pager
  • Filters?
  • Sort?
  • Link in the toolbar and display in a popin?
• Create a replication log when pulling?