Ukidss multiple target query_region

One of the most useful features of the Astroquery Vizier module is the ability to search for multiple targets simultaneously, since it minimizes network traffic/server load. Having a similar capability in the Ukidss module would be very helpful to add, assuming the WFCAM Science Archive supports multi-target searches.

Start by comparing the Astroquery Vizier module's multi-target query_region behavior with the Ukidss module. Check whether the WFCAM Science Archive supports multi-target searches and identify the Ukidss query_region entry point. Done means Ukidss can search multiple targets while minimizing requests, with coverage for the resulting behavior.

Written by the indexing model from the issue text.