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.

examples/draw-features.js

@@ -1,17 +1,17 @@
+import Draw from '../src/ol/interaction/Draw.js';
 import Map from '../src/ol/Map.js';
 import View from '../src/ol/View.js';
-import Draw from '../src/ol/interaction/Draw.js';
-import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
 import {OSM, Vector as VectorSource} from '../src/ol/source.js';
+import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
 
 const raster = new TileLayer({
-  source: new OSM()
+  source: new OSM(),
 });
 
 const source = new VectorSource({wrapX: false});
 
 const vector = new VectorLayer({
-  source: source
+  source: source,
 });
 
 const map = new Map({
@@ -19,8 +19,8 @@ const map = new Map({
   target: 'map',
   view: new View({
     center: [-11000000, 4600000],
-    zoom: 4
-  })
+    zoom: 4,
+  }),
 });
 
 const typeSelect = document.getElementById('type');
@@ -31,17 +31,16 @@ function addInteraction() {
   if (value !== 'None') {
     draw = new Draw({
       source: source,
-      type: typeSelect.value
+      type: typeSelect.value,
     });
     map.addInteraction(draw);
   }
 }
 
-
 /**
  * Handle change event.
  */
-typeSelect.onchange = function() {
+typeSelect.onchange = function () {
   map.removeInteraction(draw);
   addInteraction();
 };