Make code prettier

This updates ESLint and our shared eslint-config-openlayers to use Prettier.  Most formatting changes were automatically applied with this:

    npm run lint -- --fix

A few manual changes were required:

 * In `examples/offscreen-canvas.js`, the `//eslint-disable-line` comment needed to be moved to the appropriate line to disable the error about the `'worker-loader!./offscreen-canvas.worker.js'` import.
 * In `examples/webpack/exapmle-builder.js`, spaces could not be added after a couple `function`s for some reason.  While editing this, I reworked `ExampleBuilder` to be a class.
 * In `src/ol/format/WMSGetFeatureInfo.js`, the `// @ts-ignore` comment needed to be moved down one line so it applied to the `parsersNS` argument.

src/ol/ImageBase.js

@@ -1,15 +1,14 @@
 /**
  * @module ol/ImageBase
  */
-import {abstract} from './util.js';
 import EventTarget from './events/Target.js';
 import EventType from './events/EventType.js';
+import {abstract} from './util.js';
 
 /**
  * @abstract
  */
 class ImageBase extends EventTarget {
-
   /**
    * @param {import("./extent.js").Extent} extent Extent.
    * @param {number|undefined} resolution Resolution.
@@ -17,7 +16,6 @@ class ImageBase extends EventTarget {
    * @param {import("./ImageState.js").default} state State.
    */
   constructor(extent, resolution, pixelRatio, state) {
-
     super();
 
     /**
@@ -43,7 +41,6 @@ class ImageBase extends EventTarget {
      * @type {import("./ImageState.js").default}
      */
     this.state = state;
-
   }
 
   /**
@@ -98,5 +95,4 @@ class ImageBase extends EventTarget {
   }
 }
 
-
 export default ImageBase;