fix(playlist-plugin): expose playlist plugin version

Expose the plugin version by adding a static getter `VERSION` to all plugins and
components. To retrieve the version of the component on a given player simply do:

```javascript
// Retrieve the player
const player = document.getElementsByTagName('video')[0].parentElement.player;
// Print the component version
console.log(player.pillarboxPlaylist().version());
```

packages/pillarbox-playlist/src/pillarbox-playlist.js

@@ -1,4 +1,5 @@
 import videojs from 'video.js';
+import { version } from '../package.json';
 
 /**
  * @ignore
@@ -467,6 +468,10 @@ export class PillarboxPlaylist extends Plugin {
       currentIndex: this.currentIndex_
     });
   }
+
+  static get VERSION() {
+    return version;
+  }
 }
 
 PillarboxPlaylist.prototype.options_ = {

packages/skip-button/src/skip-button.js

@@ -75,9 +75,12 @@ class SkipButton extends Button {
     this.controlText(text);
     this.show();
   }
+
+  static get VERSION() {
+    return version;
+  }
 }
 
-SkipButton.VERSION = version;
 pillarbox.registerComponent('SkipButton', SkipButton);
 
 export default SkipButton;

scripts/template/src/{{kebabCase name}}.js.hbs

@@ -22,9 +22,12 @@ class {{properCase name}} extends Plugin {
   constructor(player, options) {
     super(player, options);
   }
+
+  static get VERSION() {
+    return version;
+  }
 }
 
-{{properCase name}}.VERSION = version;
 {{platform}}.registerPlugin('{{camelCase name}}', {{properCase name}});
 {{else}}
 /**
@@ -54,9 +57,12 @@ class {{properCase name}} extends {{type}} {
   handleLanguagechange() {
     super.handleLanguagechange();
   }
+
+  static get VERSION() {
+    return version;
+  }
 }
 
-{{properCase name}}.VERSION = version;
 {{platform}}.registerComponent('{{properCase name}}', {{properCase name}});
 {{/ifEq}}