allow scale to be two dimensional

add getScaleArray() method

test two dimension scale icons
test two dimension scale text

add example of icon and label scaling
use smaller icon and larger interval
test two dimensional scale icons
test two dimensional scale icons

src/ol/style/Icon.js

@@ -36,7 +36,7 @@ import {getUid} from '../util.js';
  * @property {import("./IconOrigin.js").default} [offsetOrigin='top-left'] Origin of the offset: `bottom-left`, `bottom-right`,
  * `top-left` or `top-right`.
  * @property {number} [opacity=1] Opacity of the icon.
- * @property {number} [scale=1] Scale.
+ * @property {number|import("../size.js").Size} [scale=1] Scale.
  * @property {boolean} [rotateWithView=false] Whether to rotate the icon with the view.
  * @property {number} [rotation=0] Rotation in radians (positive rotation clockwise).
  * @property {import("../size.js").Size} [size] Icon size in pixel. Can be used together with `offset` to define the
@@ -69,7 +69,7 @@ class Icon extends ImageStyle {
     const rotation = options.rotation !== undefined ? options.rotation : 0;
 
     /**
-     * @type {number}
+     * @type {number|import("../size.js").Size}
      */
     const scale = options.scale !== undefined ? options.scale : 1;
 
@@ -215,6 +215,7 @@ class Icon extends ImageStyle {
    * @api
    */
   clone() {
+    const scale = this.getScale();
     return new Icon({
       anchor: this.anchor_.slice(),
       anchorOrigin: this.anchorOrigin_,
@@ -230,7 +231,7 @@ class Icon extends ImageStyle {
       offsetOrigin: this.offsetOrigin_,
       size: this.size_ !== null ? this.size_.slice() : undefined,
       opacity: this.getOpacity(),
-      scale: this.getScale(),
+      scale: Array.isArray(scale) ? scale.slice() : scale,
       rotation: this.getRotation(),
       rotateWithView: this.getRotateWithView(),
     });