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/heatmap-layer/main.js

@@ -1,23 +1,23 @@
+import KML from '../../../src/ol/format/KML.js';
 import Map from '../../../src/ol/Map.js';
-import View from '../../../src/ol/View.js';
 import TileLayer from '../../../src/ol/layer/Tile.js';
+import VectorSource from '../../../src/ol/source/Vector.js';
+import View from '../../../src/ol/View.js';
 import XYZ from '../../../src/ol/source/XYZ.js';
 import {Heatmap as HeatmapLayer} from '../../../src/ol/layer.js';
-import VectorSource from '../../../src/ol/source/Vector.js';
-import KML from '../../../src/ol/format/KML.js';
 
 const vector = new HeatmapLayer({
   source: new VectorSource({
     url: '/data/2012_Earthquakes_Mag5.kml',
     format: new KML({
-      extractStyles: false
-    })
+      extractStyles: false,
+    }),
   }),
   blur: 3,
-  radius: 3
+  radius: 3,
 });
 
-vector.getSource().on('addfeature', function(event) {
+vector.getSource().on('addfeature', function (event) {
   const name = event.feature.get('name');
   const magnitude = parseFloat(name.substr(2));
   event.feature.set('weight', magnitude - 5);
@@ -26,8 +26,8 @@ vector.getSource().on('addfeature', function(event) {
 const raster = new TileLayer({
   source: new XYZ({
     url: '/data/tiles/satellite/{z}/{x}/{y}.jpg',
-    transition: 0
-  })
+    transition: 0,
+  }),
 });
 
 new Map({
@@ -35,10 +35,10 @@ new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 0
-  })
+    zoom: 0,
+  }),
 });
 
 render({
-  message: 'Heatmap layer renders properly using webgl'
+  message: 'Heatmap layer renders properly using webgl',
 });