Fix bug related with pagination

There was a bug which avoided to render the errorCode with "details=on". Render methods have been modified and also some unit tests that were broken with the modifications.
I don't follow you here.
The release method 'destroys' the QCR.
Doing the release before is almost like removing the value of the render and check.
At least, only the contextElementResponseVector is released.
I can't even see any reason to call the release method, if the test is not to see whether the release method works.
But, that is not the case.
Who cares whether the unit tests leaks memory?