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/mapguide-untiled.js

@@ -1,16 +1,15 @@
-import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import ImageLayer from '../src/ol/layer/Image.js';
 import ImageMapGuide from '../src/ol/source/ImageMapGuide.js';
+import Map from '../src/ol/Map.js';
+import View from '../src/ol/View.js';
 
 const mdf = 'Library://Samples/Sheboygan/Maps/Sheboygan.MapDefinition';
-const agentUrl =
-    'http://138.197.230.93:8008/mapguide/mapagent/mapagent.fcgi?';
+const agentUrl = 'http://138.197.230.93:8008/mapguide/mapagent/mapagent.fcgi?';
 const bounds = [
   -87.865114442365922,
   43.665065564837931,
   -87.595394059497067,
-  43.823852564430069
+  43.823852564430069,
 ];
 const map = new Map({
   layers: [
@@ -26,16 +25,16 @@ const map = new Map({
           FORMAT: 'PNG',
           VERSION: '3.0.0',
           USERNAME: 'OLGuest',
-          PASSWORD: 'olguest'
+          PASSWORD: 'olguest',
         },
-        ratio: 2
-      })
-    })
+        ratio: 2,
+      }),
+    }),
   ],
   target: 'map',
   view: new View({
     center: [-87.7302542509315, 43.744459064634],
     projection: 'EPSG:4326',
-    zoom: 12
-  })
+    zoom: 12,
+  }),
 });