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/cluster.js

@@ -1,11 +1,16 @@
 import Feature from '../src/ol/Feature.js';
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import Point from '../src/ol/geom/Point.js';
-import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
+import View from '../src/ol/View.js';
+import {
+  Circle as CircleStyle,
+  Fill,
+  Stroke,
+  Style,
+  Text,
+} from '../src/ol/style.js';
 import {Cluster, OSM, Vector as VectorSource} from '../src/ol/source.js';
-import {Circle as CircleStyle, Fill, Stroke, Style, Text} from '../src/ol/style.js';
-
+import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
 
 const distance = document.getElementById('distance');
 
@@ -18,18 +23,18 @@ for (let i = 0; i < count; ++i) {
 }
 
 const source = new VectorSource({
-  features: features
+  features: features,
 });
 
 const clusterSource = new Cluster({
   distance: parseInt(distance.value, 10),
-  source: source
+  source: source,
 });
 
 const styleCache = {};
 const clusters = new VectorLayer({
   source: clusterSource,
-  style: function(feature) {
+  style: function (feature) {
     const size = feature.get('features').length;
     let style = styleCache[size];
     if (!style) {
@@ -37,27 +42,27 @@ const clusters = new VectorLayer({
         image: new CircleStyle({
           radius: 10,
           stroke: new Stroke({
-            color: '#fff'
+            color: '#fff',
           }),
           fill: new Fill({
-            color: '#3399CC'
-          })
+            color: '#3399CC',
+          }),
         }),
         text: new Text({
           text: size.toString(),
           fill: new Fill({
-            color: '#fff'
-          })
-        })
+            color: '#fff',
+          }),
+        }),
       });
       styleCache[size] = style;
     }
     return style;
-  }
+  },
 });
 
 const raster = new TileLayer({
-  source: new OSM()
+  source: new OSM(),
 });
 
 const map = new Map({
@@ -65,10 +70,10 @@ const map = new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 2
-  })
+    zoom: 2,
+  }),
 });
 
-distance.addEventListener('input', function() {
+distance.addEventListener('input', function () {
   clusterSource.setDistance(parseInt(distance.value, 10));
 });