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/render-geometry.js

@@ -1,7 +1,6 @@
+import {Circle as CircleStyle, Fill, Stroke, Style} from '../src/ol/style.js';
 import {LineString, Point, Polygon} from '../src/ol/geom.js';
 import {toContext} from '../src/ol/render.js';
-import {Circle as CircleStyle, Fill, Stroke, Style} from '../src/ol/style.js';
-
 
 const canvas = document.getElementById('canvas');
 const vectorContext = toContext(canvas.getContext('2d'), {size: [100, 100]});
@@ -14,11 +13,25 @@ const style = new Style({
   image: new CircleStyle({
     radius: 10,
     fill: fill,
-    stroke: stroke
-  })
+    stroke: stroke,
+  }),
 });
 vectorContext.setStyle(style);
 
-vectorContext.drawGeometry(new LineString([[10, 10], [90, 90]]));
-vectorContext.drawGeometry(new Polygon([[[2, 2], [98, 2], [2, 98], [2, 2]]]));
+vectorContext.drawGeometry(
+  new LineString([
+    [10, 10],
+    [90, 90],
+  ])
+);
+vectorContext.drawGeometry(
+  new Polygon([
+    [
+      [2, 2],
+      [98, 2],
+      [2, 98],
+      [2, 2],
+    ],
+  ])
+);
 vectorContext.drawGeometry(new Point([88, 88]));