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.

rendering/cases/icon-opacity/main.js

@@ -1,11 +1,14 @@
-import Map from '../../../src/ol/Map.js';
-import View from '../../../src/ol/View.js';
-import {Vector as VectorLayer, Tile as TileLayer} from '../../../src/ol/layer.js';
-import {Vector as VectorSource, XYZ} from '../../../src/ol/source.js';
-import Point from '../../../src/ol/geom/Point.js';
 import Feature from '../../../src/ol/Feature.js';
+import Map from '../../../src/ol/Map.js';
+import Point from '../../../src/ol/geom/Point.js';
+import View from '../../../src/ol/View.js';
+import {Icon, Style} from '../../../src/ol/style.js';
+import {
+  Tile as TileLayer,
+  Vector as VectorLayer,
+} from '../../../src/ol/layer.js';
+import {Vector as VectorSource, XYZ} from '../../../src/ol/source.js';
 import {fromLonLat} from '../../../src/ol/proj.js';
-import {Style, Icon} from '../../../src/ol/style.js';
 
 const center = fromLonLat([8.6, 50.1]);
 
@@ -13,35 +16,31 @@ new Map({
   layers: [
     new TileLayer({
       source: new XYZ({
-        url: '/data/tiles/satellite/{z}/{x}/{y}.jpg'
-      })
+        url: '/data/tiles/satellite/{z}/{x}/{y}.jpg',
+      }),
     }),
     new VectorLayer({
-      style: function() {
+      style: function () {
         return new Style({
           image: new Icon({
             opacity: 0.5,
             src: '/data/icon.png',
             anchor: [0.5, 46],
             anchorXUnits: 'fraction',
-            anchorYUnits: 'pixels'
-          })
+            anchorYUnits: 'pixels',
+          }),
         });
       },
       source: new VectorSource({
-        features: [
-          new Feature(
-            new Point(center)
-          )
-        ]
-      })
-    })
+        features: [new Feature(new Point(center))],
+      }),
+    }),
   ],
   target: 'map',
   view: new View({
     center: center,
-    zoom: 3
-  })
+    zoom: 3,
+  }),
 });
 
 render();