[REF] start unravelling the way we retrieve the saved search

[REF] start unravelling the way we retrieve the saved search

We have 3 types of saved searches
- search kit
- legacy core searches
- legacy custom searches

The only information these 3 need to load is the savedSearch details and
the group ID (to add in the add & exclude). The wrangling of the params should
happen in the getSql functions - which we can think about being in a listener once
they have standard inputs & outputs. However, to get to that point
we want to standardise those inputs & outputs. This removes
only point of randomness - ie savedSearch has a consistent value & the wrangling
of what is in it is pushed closer to the relevant functions