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.

rendering/cases/source-raster/main.js

@@ -1,22 +1,24 @@
-import Map from '../../../src/ol/Map.js';
-import View from '../../../src/ol/View.js';
 import ImageLayer from '../../../src/ol/layer/Image.js';
+import Map from '../../../src/ol/Map.js';
 import RasterSource from '../../../src/ol/source/Raster.js';
+import View from '../../../src/ol/View.js';
 import XYZ from '../../../src/ol/source/XYZ.js';
 
 const raster = new RasterSource({
-  sources: [new XYZ({
-    url: '/data/tiles/osm/{z}/{x}/{y}.png',
-    transition: 0
-  })],
+  sources: [
+    new XYZ({
+      url: '/data/tiles/osm/{z}/{x}/{y}.png',
+      transition: 0,
+    }),
+  ],
   threads: 0, // Avoid using workers to work with puppeteer
-  operation: function(pixels) {
+  operation: function (pixels) {
     const pixel = pixels[0];
     const red = pixel[0];
     pixel[0] = pixel[2];
     pixel[2] = red;
     return pixel;
-  }
+  },
 });
 
 new Map({
@@ -24,9 +26,8 @@ new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 0
-  })
+    zoom: 0,
+  }),
 });
 
 render();
-