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/xyz-retina.js

@@ -1,9 +1,9 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
-import TileLayer from '../src/ol/layer/Tile.js';
-import {transform, transformExtent} from '../src/ol/proj.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 XYZ from '../src/ol/source/XYZ.js';
+import {transform, transformExtent} from '../src/ol/proj.js';
 
 const mapMinZoom = 1;
 const mapMaxZoom = 15;
@@ -13,24 +13,24 @@ const map = new Map({
   target: 'map',
   layers: [
     new TileLayer({
-      source: new OSM()
+      source: new OSM(),
     }),
     new TileLayer({
       extent: transformExtent(mapExtent, 'EPSG:4326', 'EPSG:3857'),
       source: new XYZ({
-        attributions: 'Tiles © USGS, rendered with ' +
-            '<a href="http://www.maptiler.com/">MapTiler</a>',
+        attributions:
+          'Tiles © USGS, rendered with ' +
+          '<a href="http://www.maptiler.com/">MapTiler</a>',
         url: 'https://tileserver.maptiler.com/grandcanyon@2x/{z}/{x}/{y}.png',
         tilePixelRatio: 2, // THIS IS IMPORTANT
         minZoom: mapMinZoom,
-        maxZoom: mapMaxZoom
-      })
-    })
+        maxZoom: mapMaxZoom,
+      }),
+    }),
   ],
   view: new View({
     projection: 'EPSG:3857',
-    center: transform([-112.18688965, 36.057944835],
-      'EPSG:4326', 'EPSG:3857'),
-    zoom: 12
-  })
+    center: transform([-112.18688965, 36.057944835], 'EPSG:4326', 'EPSG:3857'),
+    zoom: 12,
+  }),
 });