View / add a constrainResolution option

This introduces a breaking change.

This options replaces the various `constrainResolution` options on interactions
and the `fit` method.

Since constraints are now the responsibility of the View, the fact that intermediary
zoom levels are allowed or not is now set in the view options.

By default, the view resolution is unconstrained.

src/ol/interaction/MouseWheelZoom.js

@@ -34,9 +34,6 @@ export const Mode = {
  * {@link module:ol/events/condition~always}.
  * @property {number} [duration=250] Animation duration in milliseconds.
  * @property {number} [timeout=80] Mouse wheel timeout duration in milliseconds.
- * @property {boolean} [constrainResolution=false] When using a trackpad or
- * magic mouse, zoom to the closest integer zoom level after the scroll gesture
- * ends.
  * @property {boolean} [useAnchor=true] Enable zooming using the mouse's
  * location as the anchor. When set to `false`, zooming in and out will zoom to
  * the center of the screen instead of zooming on the mouse's location.
@@ -82,12 +79,6 @@ class MouseWheelZoom extends Interaction {
      */
     this.useAnchor_ = options.useAnchor !== undefined ? options.useAnchor : true;
 
-    /**
-     * @private
-     * @type {boolean}
-     */
-    this.constrainResolution_ = options.constrainResolution || false;
-
     /**
      * @private
      * @type {import("../events/condition.js").Condition}
@@ -238,7 +229,7 @@ class MouseWheelZoom extends Interaction {
       }
       view.setResolution(resolution);
 
-      if (rebound === 0 && this.constrainResolution_) {
+      if (rebound === 0) {
         const zoomDelta = delta > 0 ? -1 : 1;
         const newZoom = view.getValidZoomLevel(view.getZoom() + zoomDelta);
         view.animate({

src/ol/interaction/PinchZoom.js

@@ -10,8 +10,6 @@ import PointerInteraction, {centroid as centroidFromPointers} from './Pointer.js
 /**
  * @typedef {Object} Options
  * @property {number} [duration=400] Animation duration in milliseconds.
- * @property {boolean} [constrainResolution=false] Zoom to the closest integer
- * zoom level after the pinch gesture ends.
  */
 
 
@@ -37,12 +35,6 @@ class PinchZoom extends PointerInteraction {
 
     super(pointerOptions);
 
-    /**
-     * @private
-     * @type {boolean}
-     */
-    this.constrainResolution_ = options.constrainResolution || false;
-
     /**
      * @private
      * @type {import("../coordinate.js").Coordinate}