Refactor: Move legacy:search to feature:search

[shamim-emon]

• Fixes Move legacy:search to feature:search #9205

[kewisch]

@asoucar here are some of the refactorings Shamim and Wolf have been working on. We're aiming to make the modules in the feature directory fairly self-contained, to reduce dependencies and build time. What goes into the feature modules should be "the way things are intended to be". The account object is very broadly (and sometimes wrongly) used, so we need to be careful on how dependencies work here.

This is a bit over my head to really review well, if this is straightforward to you then feel free to take a look.

[asoucar]

I had the one actual code question but otherwise the code looks fine and like it would work. I don't feel comfortable enough with my understanding of the expected behavior of the search functionality at this moment to actually approve