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/wkt.js

@@ -1,28 +1,29 @@
 import Map from '../src/ol/Map.js';
 import View from '../src/ol/View.js';
 import WKT from '../src/ol/format/WKT.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 wkt = 'POLYGON((10.689 -25.092, 34.595 ' +
-    '-20.170, 38.814 -35.639, 13.502 ' +
-    '-39.155, 10.689 -25.092))';
+const wkt =
+  'POLYGON((10.689 -25.092, 34.595 ' +
+  '-20.170, 38.814 -35.639, 13.502 ' +
+  '-39.155, 10.689 -25.092))';
 
 const format = new WKT();
 
 const feature = format.readFeature(wkt, {
   dataProjection: 'EPSG:4326',
-  featureProjection: 'EPSG:3857'
+  featureProjection: 'EPSG:3857',
 });
 
 const vector = new VectorLayer({
   source: new VectorSource({
-    features: [feature]
-  })
+    features: [feature],
+  }),
 });
 
 const map = new Map({
@@ -30,6 +31,6 @@ const map = new Map({
   target: 'map',
   view: new View({
     center: [2952104.0199, -3277504.823],
-    zoom: 4
-  })
+    zoom: 4,
+  }),
 });