Allow isochrone analysis for multi-isochrones
Moved from old gitlab (dbis-git).
By now an analysis in the UI looks like it can only be triggered with a single query point. In fact this is not true, since in the settings multiple isochrones can be calculated (MultiIsochrone mode) which then can be analyses (in this case all calculated isochrones are regarded during calculation).
Maybe there is a better way to do this (hopefully), but at the moment I am out of ideas HOW to do this in the UI (the algorithms are already capable of calculating with multiple queryPoints).