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/overviewmap-custom.js

@@ -1,10 +1,12 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
-import {defaults as defaultControls, OverviewMap} from '../src/ol/control.js';
-import {defaults as defaultInteractions, DragRotateAndZoom} from '../src/ol/interaction.js';
-import TileLayer from '../src/ol/layer/Tile.js';
 import OSM from '../src/ol/source/OSM.js';
-
+import TileLayer from '../src/ol/layer/Tile.js';
+import View from '../src/ol/View.js';
+import {
+  DragRotateAndZoom,
+  defaults as defaultInteractions,
+} from '../src/ol/interaction.js';
+import {OverviewMap, defaults as defaultControls} from '../src/ol/control.js';
 
 const rotateWithView = document.getElementById('rotateWithView');
 
@@ -14,35 +16,32 @@ const overviewMapControl = new OverviewMap({
   layers: [
     new TileLayer({
       source: new OSM({
-        'url': 'https://{a-c}.tile.thunderforest.com/cycle/{z}/{x}/{y}.png' +
-            '?apikey=0e6fc415256d4fbb9b5166a718591d71'
-      })
-    })
+        'url':
+          'https://{a-c}.tile.thunderforest.com/cycle/{z}/{x}/{y}.png' +
+          '?apikey=0e6fc415256d4fbb9b5166a718591d71',
+      }),
+    }),
   ],
   collapseLabel: '\u00BB',
   label: '\u00AB',
-  collapsed: false
+  collapsed: false,
 });
 
-rotateWithView.addEventListener('change', function() {
+rotateWithView.addEventListener('change', function () {
   overviewMapControl.setRotateWithView(this.checked);
 });
 
 const map = new Map({
-  controls: defaultControls().extend([
-    overviewMapControl
-  ]),
-  interactions: defaultInteractions().extend([
-    new DragRotateAndZoom()
-  ]),
+  controls: defaultControls().extend([overviewMapControl]),
+  interactions: defaultInteractions().extend([new DragRotateAndZoom()]),
   layers: [
     new TileLayer({
-      source: new OSM()
-    })
+      source: new OSM(),
+    }),
   ],
   target: 'map',
   view: new View({
     center: [500000, 6000000],
-    zoom: 7
-  })
+    zoom: 7,
+  }),
 });