Extend maximum length of selected primary table labels

The maximum length of most preferred/non-preferred labels is either 255 or 1024 characters. For selected primary tables, it would be useful to support narrative-length label text. The limit should be extended to ~16000 characters for the following:

ca_collections
ca_occurrences
ca_object_lots
ca_objects
ca_tour_stops
ca_loans
ca_movements
ca_object_representations