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/render/canvas/BuilderGroup.js

@@ -2,13 +2,12 @@
  * @module ol/render/canvas/BuilderGroup
  */
 
-import {createEmpty} from '../../extent.js';
 import Builder from './Builder.js';
 import ImageBuilder from './ImageBuilder.js';
 import LineStringBuilder from './LineStringBuilder.js';
 import PolygonBuilder from './PolygonBuilder.js';
 import TextBuilder from './TextBuilder.js';
-
+import {createEmpty} from '../../extent.js';
 
 /**
  * @type {Object<import("./BuilderType").default, typeof Builder>}
@@ -19,10 +18,9 @@ const BATCH_CONSTRUCTORS = {
   'Image': ImageBuilder,
   'LineString': LineStringBuilder,
   'Polygon': PolygonBuilder,
-  'Text': TextBuilder
+  'Text': TextBuilder,
 };
 
-
 class BuilderGroup {
   /**
    * @param {number} tolerance Tolerance.
@@ -32,7 +30,6 @@ class BuilderGroup {
    * @param {boolean} declutter Decluttering enabled.
    */
   constructor(tolerance, maxExtent, resolution, pixelRatio, declutter) {
-
     /**
      * @type {boolean}
      * @private
@@ -126,8 +123,12 @@ class BuilderGroup {
     let replay = replays[builderType];
     if (replay === undefined) {
       const Constructor = BATCH_CONSTRUCTORS[builderType];
-      replay = new Constructor(this.tolerance_, this.maxExtent_,
-        this.resolution_, this.pixelRatio_);
+      replay = new Constructor(
+        this.tolerance_,
+        this.maxExtent_,
+        this.resolution_,
+        this.pixelRatio_
+      );
       replays[builderType] = replay;
     }
     return replay;