Use npm to manage litegraph dependency (#45)

* Add comfyui-litegraph dep

* remove static copy

* Remove litegraph impl

* Fix various issues

* LiteGraph import

* Fix test ref issue

* Change to stable version of litegraph

* update README

src/extensions/core/simpleTouchSupport.ts

@@ -1,4 +1,5 @@
 import { app } from "../../scripts/app";
+import { LGraphCanvas, LiteGraph } from "comfyui-litegraph";
 
 let touchZooming;
 let touchCount = 0;