Task/392 service path service path unit tests

### Description
- Unit tests for queryContext
- Initial sanity check of Service Path, with corresponding unit tests

Actually, it doesn't is a matter of style, but of "soundness". I mean, it wouldn't be the first time a "butterfly effect" happens and changing something that supossely only affects (for example) to context element response rendering also affect to status code. Covering all the response in the test ensure early detection of this problems.

However, it you think it is a "dull" task and doesn't worth the time at the present moment, put a `//FIXME this test needs check the complete response (pending)` and I will try to do it in the future.