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/layer/vectorimage.test.js

@@ -1,30 +1,28 @@
 import Feature from '../../../../src/ol/Feature.js';
-import Point from '../../../../src/ol/geom/Point.js';
 import Map from '../../../../src/ol/Map.js';
-import View from '../../../../src/ol/View.js';
+import Point from '../../../../src/ol/geom/Point.js';
 import VectorImageLayer from '../../../../src/ol/layer/VectorImage.js';
 import VectorSource from '../../../../src/ol/source/Vector.js';
+import View from '../../../../src/ol/View.js';
 
-describe('ol/layer/VectorImage', function() {
-
-  describe('#getFeatures()', function() {
-
+describe('ol/layer/VectorImage', function () {
+  describe('#getFeatures()', function () {
     let map, layer;
 
-    beforeEach(function() {
+    beforeEach(function () {
       layer = new VectorImageLayer({
         source: new VectorSource({
           features: [
             new Feature({
               geometry: new Point([-1000000, 0]),
-              name: 'feature1'
+              name: 'feature1',
             }),
             new Feature({
               geometry: new Point([1000000, 0]),
-              name: 'feture2'
-            })
-          ]
-        })
+              name: 'feture2',
+            }),
+          ],
+        }),
       });
       const container = document.createElement('div');
       container.style.width = '256px';
@@ -32,30 +30,26 @@ describe('ol/layer/VectorImage', function() {
       document.body.appendChild(container);
       map = new Map({
         target: container,
-        layers: [
-          layer
-        ],
+        layers: [layer],
         view: new View({
           zoom: 2,
-          center: [0, 0]
-        })
+          center: [0, 0],
+        }),
       });
     });
 
-    afterEach(function() {
+    afterEach(function () {
       document.body.removeChild(map.getTargetElement());
       map.setTarget(null);
     });
 
-    it('detects features properly', function(done) {
+    it('detects features properly', function (done) {
       map.renderSync();
       const pixel = map.getPixelFromCoordinate([-1000000, 0]);
-      layer.getFeatures(pixel).then(function(features) {
+      layer.getFeatures(pixel).then(function (features) {
         expect(features[0].get('name')).to.be('feature1');
         done();
       });
     });
-
   });
-
 });