Query on `searches` field when searching for superevents as well

There is a need when searching for superevents to filter based on the searches field.

One scenario where this matters is when doing searches with Burst events, where some of these events have search='AllSky' whiles others search='BBH' or search='IMBH'. We would like to use wider windows for AllSky events ([-60, +600] sec) since the progenitors are likely SN while the other two searches are CBCs and therefore should use shorter windows ([-1, +5] sec).

Once this is complete, we can separate these two sets in gwcelery as separate searches with their own time windows.

These changes would mainly occur here: https://git.ligo.org/lscsoft/raven/-/blob/master/ligo/raven/search.py#L80-88 and most of the work would be in fixing the messaging in search.search(): https://git.ligo.org/lscsoft/raven/-/blob/master/ligo/raven/search.py#L125-195