Fix that the search panel is very slow to return results (due to RLS)

[Venryx]

Ideas:

• Try changing the RLS subfunctions to use "SELECT" and such, to enable caching of their results across rows. (as discussed here)
• Try creating a view, to enable running some RLS-related queries once (to then be part of a JOIN), and thus avoiding expensive fresh queries per row.

[Venryx]

M-A got search running much faster (~2.5s, vs old of between 13.5 and 40s depending on query/admin-status), which is good enough for now. (thus changing task priority to "mid term")