Refactor ExcalidrawElement (#874)

* Get rid of isSelected, canvas, canvasZoom, canvasOffsetX and canvasOffsetY on ExcalidrawElement.

* Fix most unit tests. Fix cmd a. Fix alt drag

* Focus on paste

* shift select should include previously selected items

* Fix last test

* Move this.shape out of ExcalidrawElement and into a WeakMap

src/index-node.ts

@@ -1,4 +1,5 @@
 import { exportToCanvas } from "./scene/export";
+import { getDefaultAppState } from "./appState";
 
 const { registerFont, createCanvas } = require("canvas");
 
@@ -16,7 +17,6 @@ const elements = [
     strokeWidth: 1,
     roughness: 1,
     opacity: 100,
-    isSelected: false,
     seed: 749612521,
   },
   {
@@ -32,7 +32,6 @@ const elements = [
     strokeWidth: 1,
     roughness: 1,
     opacity: 100,
-    isSelected: false,
     seed: 952056308,
   },
   {
@@ -48,7 +47,6 @@ const elements = [
     strokeWidth: 1,
     roughness: 1,
     opacity: 100,
-    isSelected: false,
     seed: 1683771448,
     text: "test",
     font: "20px Virgil",
@@ -60,6 +58,7 @@ registerFont("./public/FG_Virgil.ttf", { family: "Virgil" });
 registerFont("./public/Cascadia.ttf", { family: "Cascadia" });
 const canvas = exportToCanvas(
   elements as any,
+  getDefaultAppState(),
   {
     exportBackground: true,
     viewBackgroundColor: "#ffffff",