Some search query classes have missing, additional or incorrectly named attributes

Some examples:

• `operator` is not passed to the backend in MatchQuery

• DocIdQuery has a `doc_ids` attribute whereas the server expects `ids` which results in an internal server error

• `operator` is in all search query classes, even though it's only needed for MatchQuery

To do:

• Review all the different types of search queries to spot and fix any other similar issues.

• Write some more tests where appropriate