ENH: adding extra, non-spatial filter keyword to `query_region` methods

E.g. for IRSA, the `query_region` method is building up an ADQL query under the hood. So, especially for the `All-Sky` spatial use-case it would be useful to be able to specify other filtering criteria.

This maybe useful for other modules, too, at least for the ones using TAP under the hood for their `query_region`.

Begin by tracing the IRSA query_region implementation and its ADQL construction, then compare the other TAP-backed query_region methods mentioned in the issue. Done means callers can provide non-spatial filtering criteria, including for the All-Sky case, wherever the supported query_region methods use TAP.

Written by the indexing model from the issue text.