TypeScript conversion groundwork (#163)

* ContextMenu ES6 class conversion

* Fix compat with extensions

* CurveEditor ES6 class conversion

* Split most of the LiteGraph global out to a class

* Move remainder of LiteGraph global to class file

* Remove IIFE wrapper

* Fix jest tests throwing due to type narrowing

test/LGraph.test.ts

@@ -12,13 +12,16 @@ describe("LegacyLGraph Compatibility Layer", () => {
 
   test("LGraph can be extended via prototype", () => {
     const graph = new LGraph();
+    // @ts-expect-error Should always be an error.
     LGraph.prototype.newMethod = function () {
       return "New method added via prototype";
     };
+    // @ts-expect-error Should always be an error.
     expect(graph.newMethod()).toBe("New method added via prototype");
   });
 
   test("LegacyLGraph is correctly assigned to LiteGraph", () => {
+    // @ts-expect-error Fixed later in the TS conversion process.
     expect(LiteGraph.LGraph).toBe(LGraph);
   });
 });

test/LGraphNode.test.ts

@@ -5,7 +5,9 @@ import {
 describe("LGraphNode", () => {
   it("should serialize position correctly", () => {
     const node = new LGraphNode("TestNode");
+    // @ts-expect-error Expected - not a TS class yet.
     node.pos = [10, 10];
+    // @ts-expect-error JS tests in TS format
     expect(node.pos).toEqual(new Float32Array([10, 10]));
     expect(node.serialize().pos).toEqual(new Float32Array([10, 10]));
   });