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.

rendering/cases/source-tilewms-gutter0/main.js

@@ -1,15 +1,15 @@
 import Map from '../../../src/ol/Map.js';
-import View from '../../../src/ol/View.js';
 import TileLayer from '../../../src/ol/layer/Tile.js';
 import TileWMS from '../../../src/ol/source/TileWMS.js';
+import View from '../../../src/ol/View.js';
 
 const tileWms = new TileWMS({
   params: {
-    'LAYERS': 'layer'
+    'LAYERS': 'layer',
   },
   gutter: 0,
   url: '/data/tiles/wms/wms0.png',
-  transition: 0
+  transition: 0,
 });
 
 new Map({
@@ -18,9 +18,8 @@ new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 5
-  })
+    zoom: 5,
+  }),
 });
 
 render();
-