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/worker/webgl.test.js

@@ -1,32 +1,30 @@
+import {WebGLWorkerMessageType} from '../../../../src/ol/renderer/webgl/Layer.js';
 import {create} from '../../../../src/ol/worker/webgl.js';
-import {
-  WebGLWorkerMessageType
-} from '../../../../src/ol/renderer/webgl/Layer.js';
-
-
-describe('ol/worker/webgl', function() {
 
+describe('ol/worker/webgl', function () {
   let worker;
-  beforeEach(function() {
+  beforeEach(function () {
     worker = create();
   });
 
-  afterEach(function() {
+  afterEach(function () {
     if (worker) {
       worker.terminate();
     }
     worker = null;
   });
 
-  describe('messaging', function() {
-    describe('GENERATE_BUFFERS', function() {
-      it('responds with buffer data', function(done) {
-        worker.addEventListener('error', function(error) {
+  describe('messaging', function () {
+    describe('GENERATE_BUFFERS', function () {
+      it('responds with buffer data', function (done) {
+        worker.addEventListener('error', function (error) {
           expect().fail(error.message);
         });
 
-        worker.addEventListener('message', function(event) {
-          expect(event.data.type).to.eql(WebGLWorkerMessageType.GENERATE_BUFFERS);
+        worker.addEventListener('message', function (event) {
+          expect(event.data.type).to.eql(
+            WebGLWorkerMessageType.GENERATE_BUFFERS
+          );
           expect(event.data.renderInstructions.byteLength).to.greaterThan(0);
           expect(event.data.indexBuffer.byteLength).to.greaterThan(0);
           expect(event.data.vertexBuffer.byteLength).to.greaterThan(0);
@@ -42,12 +40,11 @@ describe('ol/worker/webgl', function() {
           renderInstructions: instructions,
           customAttributesCount: 0,
           testInt: 101,
-          testString: 'abcd'
+          testString: 'abcd',
         };
 
         worker.postMessage(message);
       });
     });
   });
-
 });