Support filtering short URLs by domain

[acelaya]

Summary

Add an option to the short URLs list to filter by domain.

This would mitigate the fact that open search does not work when searching for the default domain.

[acelaya]

Finally open search has been enhanced to support searching by the default domain too, so this is finally not needed.

[acelaya]

Reopening, as this is useful on its own, and would make the endpoint more consistent with others.