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/zoomify.js

@@ -1,6 +1,6 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import TileLayer from '../src/ol/layer/Tile.js';
+import View from '../src/ol/View.js';
 import Zoomify from '../src/ol/source/Zoomify.js';
 
 const imgWidth = 4000;
@@ -12,7 +12,7 @@ const source = new Zoomify({
   url: zoomifyUrl,
   size: [imgWidth, imgHeight],
   crossOrigin: 'anonymous',
-  zDirection: -1 // Ensure we get a tile with the screen resolution or higher
+  zDirection: -1, // Ensure we get a tile with the screen resolution or higher
 });
 const extent = source.getTileGrid().getExtent();
 
@@ -23,11 +23,11 @@ const retinaSource = new Zoomify({
   crossOrigin: 'anonymous',
   zDirection: -1, // Ensure we get a tile with the screen resolution or higher
   tilePixelRatio: retinaPixelRatio, // Display retina tiles
-  tileSize: 256 / retinaPixelRatio // from a higher zoom level
+  tileSize: 256 / retinaPixelRatio, // from a higher zoom level
 });
 
 const layer = new TileLayer({
-  source: source
+  source: source,
 });
 
 const map = new Map({
@@ -38,13 +38,13 @@ const map = new Map({
     resolutions: layer.getSource().getTileGrid().getResolutions(),
     // constrain the center: center cannot be set outside this extent
     extent: extent,
-    constrainOnlyCenter: true
-  })
+    constrainOnlyCenter: true,
+  }),
 });
 map.getView().fit(extent);
 
 const control = document.getElementById('zoomifyProtocol');
-control.addEventListener('change', function(event) {
+control.addEventListener('change', function (event) {
   const value = event.currentTarget.value;
   if (value === 'zoomify') {
     layer.setSource(source);
@@ -52,5 +52,3 @@ control.addEventListener('change', function(event) {
     layer.setSource(retinaSource);
   }
 });
-
-