feat(livechat): add LiveChatPaidSticker action

lib/parser/contents/classes/livechat/items/LiveChatPaidSticker.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const Parser = require('../../..');
+const NavigationEndpoint = require('../../NavigationEndpoint');
+const Thumbnail = require('../../Thumbnail');
+const Text = require('../../Text');
+
+class LiveChatPaidSticker {
+	type = 'LiveChatPaidSticker';
+
+	constructor(data) {
+		this.id = data.id;
+
+		this.author = {
+      id: data.authorExternalChannelId,
+      name: new Text(data.authorName),
+      thumbnails: Thumbnail.fromResponse(data.authorPhoto),
+      badges: Parser.parse(data.authorBadges)
+    };
+
+		this.sticker = Thumbnail.fromResponse(data.sticker);
+		this.purchase_amount = new Text(data.purchaseAmountText).toString();
+		this.context_menu = new NavigationEndpoint(data.contextMenuEndpoint);
+		this.timestamp = Math.floor(parseInt(data.timestampUsec) / 1000);
+	}
+}
+
+module.exports = LiveChatPaidSticker;