fix crash in particle and model server from attempting to edit items that dont exist in the server

There is a potential crash in the particle/model server when an edit message contained multiple records to edit multiple items, and one of the items (early) attempted to edit an unknown ID... in this case the particle server would reject the edit (bad ID) but wouldn't consume the edit packet data and as a result future reading from the buffer would be out of sync and corrupt and cause a crash