Apply integration tests to the queryserver

We can add queryserver tests that extend the direct tests.
ie. QueryServerLikeExpressionIT extends LikeExpressionIT.

`getUrl` needs to be overridden to access the test cluster through the queryserver. We can't override static methods or fields (but getUrl needs to be static because in many cases it is used in @BeforeClass) but we could use dependency injection to inject a url-holder. This way, the QueryServer~IT tests will be shell classes that simply override initialization of the url-holder.

This could effectively double the amount of time taken to run integration tests.

Any objections to using dependency injection - or alternative solutions? Should we replicate tests across the board or selectively?