Allow SearchService#search_state to be mutated

[jcoyne]

This allows us to adjust the search_state and run a query again, without having to reinitialize the object.

This can be used in a report where you may want to iterate through a bunch of pages of results to construct a CSV.

[cbeer]

I find mutating search_state pretty surprising. I wonder if updating search_results to accept either a search_state or the search_builder would get you there?

[tpendragon]

@jcoyne Can you speak to the use case motivating wanting to do this? Like is a user asking for something and this makes that feature easier?

[jcoyne]

@tpendragon I was thinking of paging through a result set to write a report.

So, initialize the SearchService once, then call search_results, update the page in the search_state, then call search_results again, repeat until done.

In the existing code, I have to have a different SearchService instance for each page of results.

[jcoyne]

I find mutating search_state pretty surprising. I wonder if updating search_results to accept either a search_state or the search_builder would get you there?

@cbeer yes, I think that approach would work just as well.

[jrochkind]

Do we need a new test ensuring as supported tested API? I approved anyway, up to you.