Search for owners is very slow.

[ericrobskyhuntley]

This is due to .distinct() filter on the OwnerViewset. Put in place to remove duplicates, but is inducing big search delays (and probably compute costs).

https://github.com/mit-spatial-action/who-owns-mass-backend/blob/d0dc23c1bc2372a893e1ab32598ae9e9a80ac622/who_owns_mass/views.py#L23-L28