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.

src/ol/style/Circle.js

@@ -4,7 +4,6 @@
 
 import RegularShape from './RegularShape.js';
 
-
 /**
  * @typedef {Object} Options
  * @property {import("./Fill.js").default} [fill] Fill style.
@@ -13,7 +12,6 @@ import RegularShape from './RegularShape.js';
  * @property {Array<number>} [displacement=[0,0]] displacement
  */
 
-
 /**
  * @classdesc
  * Set circle style for vector features.
@@ -24,7 +22,6 @@ class CircleStyle extends RegularShape {
    * @param {Options=} opt_options Options.
    */
   constructor(opt_options) {
-
     const options = opt_options ? opt_options : {};
 
     super({
@@ -32,9 +29,9 @@ class CircleStyle extends RegularShape {
       fill: options.fill,
       radius: options.radius,
       stroke: options.stroke,
-      displacement: options.displacement !== undefined ? options.displacement : [0, 0]
+      displacement:
+        options.displacement !== undefined ? options.displacement : [0, 0],
     });
-
   }
 
   /**
@@ -47,7 +44,7 @@ class CircleStyle extends RegularShape {
       fill: this.getFill() ? this.getFill().clone() : undefined,
       stroke: this.getStroke() ? this.getStroke().clone() : undefined,
       radius: this.getRadius(),
-      displacement: this.getDisplacement().slice()
+      displacement: this.getDisplacement().slice(),
     });
     style.setOpacity(this.getOpacity());
     style.setScale(this.getScale());
@@ -66,5 +63,4 @@ class CircleStyle extends RegularShape {
   }
 }
 
-
 export default CircleStyle;