Prevent visual glitches on DataLists/DataRepeaters while collection updates

Destroying/removing records while fetching causes visual artifacts on binded controls, like "disappearing lists". This is caused because new data is received long after removing previous data from the collection.

Old records removing/destroying must be done inmediately before of adding new records to prevent these visual artifacts.

Enyo-DCO-1.1-Signed-Off-By: Rafa Bernad (rafa.bernad@newn.es)