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/drag-rotate-and-zoom.js

@@ -1,22 +1,22 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
-import {defaults as defaultInteractions, DragRotateAndZoom} from '../src/ol/interaction.js';
-import TileLayer from '../src/ol/layer/Tile.js';
 import OSM from '../src/ol/source/OSM.js';
-
+import TileLayer from '../src/ol/layer/Tile.js';
+import View from '../src/ol/View.js';
+import {
+  DragRotateAndZoom,
+  defaults as defaultInteractions,
+} from '../src/ol/interaction.js';
 
 const map = new Map({
-  interactions: defaultInteractions().extend([
-    new DragRotateAndZoom()
-  ]),
+  interactions: defaultInteractions().extend([new DragRotateAndZoom()]),
   layers: [
     new TileLayer({
-      source: new OSM()
-    })
+      source: new OSM(),
+    }),
   ],
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 2
-  })
+    zoom: 2,
+  }),
 });