View / add a resolveConstraints method to end interactions

This will help making sure that the view will come back to a "rested" state
once the interactions are over.

Interactions no longer need to handle the animation back to a rested state,
they simply call `endInteraction` with the desired duration and direction.

src/ol/interaction/DragRotateAndZoom.js

@@ -113,10 +113,8 @@ class DragRotateAndZoom extends PointerInteraction {
 
     const map = mapBrowserEvent.map;
     const view = map.getView();
-    view.endInteraction();
     const direction = this.lastScaleDelta_ - 1;
-    rotate(view, view.getRotation());
-    zoom(view, view.getResolution(), undefined, this.duration_, direction);
+    view.endInteraction(this.duration_, direction);
     this.lastScaleDelta_ = 0;
     return false;
   }