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/getfeatureinfo-image.js

@@ -1,37 +1,39 @@
-import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import ImageLayer from '../src/ol/layer/Image.js';
 import ImageWMS from '../src/ol/source/ImageWMS.js';
-
+import Map from '../src/ol/Map.js';
+import View from '../src/ol/View.js';
 
 const wmsSource = new ImageWMS({
   url: 'https://ahocevar.com/geoserver/wms',
   params: {'LAYERS': 'ne:ne'},
   serverType: 'geoserver',
-  crossOrigin: 'anonymous'
+  crossOrigin: 'anonymous',
 });
 
 const wmsLayer = new ImageLayer({
-  source: wmsSource
+  source: wmsSource,
 });
 
 const view = new View({
   center: [0, 0],
-  zoom: 1
+  zoom: 1,
 });
 
 const map = new Map({
   layers: [wmsLayer],
   target: 'map',
-  view: view
+  view: view,
 });
 
-map.on('singleclick', function(evt) {
+map.on('singleclick', function (evt) {
   document.getElementById('info').innerHTML = '';
   const viewResolution = /** @type {number} */ (view.getResolution());
   const url = wmsSource.getFeatureInfoUrl(
-    evt.coordinate, viewResolution, 'EPSG:3857',
-    {'INFO_FORMAT': 'text/html'});
+    evt.coordinate,
+    viewResolution,
+    'EPSG:3857',
+    {'INFO_FORMAT': 'text/html'}
+  );
   if (url) {
     fetch(url)
       .then((response) => response.text())
@@ -41,12 +43,12 @@ map.on('singleclick', function(evt) {
   }
 });
 
-map.on('pointermove', function(evt) {
+map.on('pointermove', function (evt) {
   if (evt.dragging) {
     return;
   }
   const pixel = map.getEventPixel(evt.originalEvent);
-  const hit = map.forEachLayerAtPixel(pixel, function() {
+  const hit = map.forEachLayerAtPixel(pixel, function () {
     return true;
   });
   map.getTargetElement().style.cursor = hit ? 'pointer' : '';