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/fractal.js

@@ -1,9 +1,9 @@
 import Feature from '../src/ol/Feature.js';
-import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import LineString from '../src/ol/geom/LineString.js';
+import Map from '../src/ol/Map.js';
 import VectorLayer from '../src/ol/layer/Vector.js';
 import VectorSource from '../src/ol/source/Vector.js';
+import View from '../src/ol/View.js';
 
 const radius = 10e6;
 const cos30 = Math.cos(Math.PI / 6);
@@ -12,15 +12,18 @@ const rise = radius * sin30;
 const run = radius * cos30;
 
 const triangle = new LineString([
-  [0, radius], [run, -rise], [-run, -rise], [0, radius]
+  [0, radius],
+  [run, -rise],
+  [-run, -rise],
+  [0, radius],
 ]);
 
 const feature = new Feature(triangle);
 
 const layer = new VectorLayer({
   source: new VectorSource({
-    features: [feature]
-  })
+    features: [feature],
+  }),
 });
 
 const map = new Map({
@@ -28,8 +31,8 @@ const map = new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 1
-  })
+    zoom: 1,
+  }),
 });
 
 function makeFractal(depth) {
@@ -59,19 +62,19 @@ function injectNodes(startNode) {
 
   // first point at 1/3 along the segment
   const firstNode = {
-    point: [start[0] + dx / 3, start[1] + dy / 3]
+    point: [start[0] + dx / 3, start[1] + dy / 3],
   };
 
   // second point at peak of _/\_
   const r = Math.sqrt(dx * dx + dy * dy) / (2 * cos30);
   const a = Math.atan2(dy, dx) + Math.PI / 6;
   const secondNode = {
-    point: [start[0] + r * Math.cos(a), start[1] + r * Math.sin(a)]
+    point: [start[0] + r * Math.cos(a), start[1] + r * Math.sin(a)],
   };
 
   // third point at 2/3 along the segment
   const thirdNode = {
-    point: [end[0] - dx / 3, end[1] - dy / 3]
+    point: [end[0] - dx / 3, end[1] - dy / 3],
   };
 
   startNode.next = firstNode;
@@ -80,15 +83,14 @@ function injectNodes(startNode) {
   thirdNode.next = endNode;
 }
 
-
 function coordsToGraph(coordinates) {
   const graph = {
-    point: coordinates[0]
+    point: coordinates[0],
   };
   const length = coordinates.length;
   for (let level = 0, node = graph; level < length - 1; ++level) {
     node.next = {
-      point: coordinates[level + 1]
+      point: coordinates[level + 1],
     };
     node = node.next;
   }
@@ -111,12 +113,11 @@ function update() {
 
 let updateTimer;
 
-
 /**
  * Regenerate fractal on depth change.  Change events are debounced so updates
  * only occur every 200ms.
  */
-depthInput.onchange = function() {
+depthInput.onchange = function () {
   window.clearTimeout(updateTimer);
   updateTimer = window.setTimeout(update, 200);
 };