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.

package.json

@@ -61,8 +61,8 @@
     "clean-css-cli": "4.3.0",
     "copy-webpack-plugin": "^5.0.4",
     "coveralls": "3.0.11",
-    "eslint": "^6.0.0",
-    "eslint-config-openlayers": "^13.0.0",
+    "eslint": "^6.8.0",
+    "eslint-config-openlayers": "^14.0.0",
     "expect.js": "0.3.1",
     "front-matter": "^3.0.2",
     "fs-extra": "^9.0.0",