Include icus items for deposit holdings analysis

[aelkiss]

Because the deposit holdings analysis is primarily for resource sharing which is (for now) a US-based service, we wanted to include icus material in that analysis.

This also exposes functionality for the mock solr response to include different records or queries, which could be useful for certain kinds of testing.

Arguably we shouldn't include nobody or pd-pvt for the purposes of this analysis since resource sharing people can't get access ot them, but the rights codes are at least now included in the report output so we can filter them out if desired.

This definitely exposes a bit of a question about how we consider what's "in copyright" for different purposes; it probably doesn't make sense to have a unilateral definition of that for holdings; future needs around overlap reporting focused around particular services might help clarify this.

[aelkiss]

I pushed something with a different approach to mocking the solr response. This is definitely exposing limitations both in the way we're testing the output of things and the assumption about the rights overall. Annoyingly, it's a pretty easy change to make, but messy to test. It was a bit messy to test to begin with too -- this at least starts to expose the possibility of mocking different responses from solr.

[coveralls]

coverage: 77.25% (-0.02%) from 77.271%
when pulling 84553d4 on deposit-analysis-icus
into a85e34f on main.

[moseshll]

I had to stare at mock_solr_search_filtered a bit to get it crowbarred into my head. The non-testing logic is simple and reasonable. APPROVE