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.

test/spec/ol/renderer/map.test.js

@@ -2,12 +2,9 @@ import Disposable from '../../../../src/ol/Disposable.js';
 import Map from '../../../../src/ol/Map.js';
 import MapRenderer from '../../../../src/ol/renderer/Map.js';
 
-
-describe('ol.renderer.Map', function() {
-
-  describe('constructor', function() {
-
-    it('createst an instance', function() {
+describe('ol.renderer.Map', function () {
+  describe('constructor', function () {
+    it('createst an instance', function () {
       const map = new Map({});
       const renderer = new MapRenderer(null, map);
       expect(renderer).to.be.a(MapRenderer);
@@ -15,7 +12,5 @@ describe('ol.renderer.Map', function() {
       renderer.dispose();
       map.dispose();
     });
-
   });
-
 });