Refactor: query execution strategy

[Maarten Mulders]

For now, only an idea: it might make sense to introduce a "strategy" for executing search queries. Possible strategies:

1. "just run it"
2. "run it, but modify some parameters"
3. "void" or "return"

This would probably make it easier to implement finding all results, even when that would exceed the maximum number of results from the remote API. Initially, it would use strategy 1, then 0 or more times strategy 2 (where the 'start' parameter is updated every time) and eventually, strategy 3 (which would return the aggregated results).