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/cartodb.js

@@ -1,47 +1,48 @@
 import Map from '../src/ol/Map.js';
-import View from '../src/ol/View.js';
 import TileLayer from '../src/ol/layer/Tile.js';
+import View from '../src/ol/View.js';
 import {CartoDB, OSM} from '../src/ol/source.js';
 
 const mapConfig = {
-  'layers': [{
-    'type': 'cartodb',
-    'options': {
-      'cartocss_version': '2.1.1',
-      'cartocss': '#layer { polygon-fill: #F00; }',
-      'sql': 'select * from european_countries_e where area > 0'
-    }
-  }]
+  'layers': [
+    {
+      'type': 'cartodb',
+      'options': {
+        'cartocss_version': '2.1.1',
+        'cartocss': '#layer { polygon-fill: #F00; }',
+        'sql': 'select * from european_countries_e where area > 0',
+      },
+    },
+  ],
 };
 
 const cartoDBSource = new CartoDB({
   account: 'documentation',
-  config: mapConfig
+  config: mapConfig,
 });
 
 const map = new Map({
   layers: [
     new TileLayer({
-      source: new OSM()
+      source: new OSM(),
     }),
     new TileLayer({
-      source: cartoDBSource
-    })
+      source: cartoDBSource,
+    }),
   ],
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 2
-  })
+    zoom: 2,
+  }),
 });
 
 function setArea(n) {
   mapConfig.layers[0].options.sql =
-      'select * from european_countries_e where area > ' + n;
+    'select * from european_countries_e where area > ' + n;
   cartoDBSource.setConfig(mapConfig);
 }
 
-
-document.getElementById('country-area').addEventListener('change', function() {
+document.getElementById('country-area').addEventListener('change', function () {
   setArea(this.value);
 });