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/wmts-ign.js

@@ -1,18 +1,17 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
-import {getWidth} from '../src/ol/extent.js';
 import TileLayer from '../src/ol/layer/Tile.js';
-import {fromLonLat, get as getProjection} from '../src/ol/proj.js';
+import View from '../src/ol/View.js';
 import WMTS from '../src/ol/source/WMTS.js';
 import WMTSTileGrid from '../src/ol/tilegrid/WMTS.js';
-
+import {fromLonLat, get as getProjection} from '../src/ol/proj.js';
+import {getWidth} from '../src/ol/extent.js';
 
 const map = new Map({
   target: 'map',
   view: new View({
     zoom: 5,
-    center: fromLonLat([5, 45])
-  })
+    center: fromLonLat([5, 45]),
+  }),
 });
 
 const resolutions = [];
@@ -28,7 +27,7 @@ for (let i = 0; i < 18; i++) {
 const tileGrid = new WMTSTileGrid({
   origin: [-20037508, 20037508],
   resolutions: resolutions,
-  matrixIds: matrixIds
+  matrixIds: matrixIds,
 });
 
 // For more information about the IGN API key see
@@ -42,13 +41,14 @@ const ign_source = new WMTS({
   projection: 'EPSG:3857',
   tileGrid: tileGrid,
   style: 'normal',
-  attributions: '<a href="http://www.geoportail.fr/" target="_blank">' +
-        '<img src="https://api.ign.fr/geoportail/api/js/latest/' +
-        'theme/geoportal/img/logo_gp.gif"></a>'
+  attributions:
+    '<a href="http://www.geoportail.fr/" target="_blank">' +
+    '<img src="https://api.ign.fr/geoportail/api/js/latest/' +
+    'theme/geoportal/img/logo_gp.gif"></a>',
 });
 
 const ign = new TileLayer({
-  source: ign_source
+  source: ign_source,
 });
 
 map.addLayer(ign);