feat: in canvas links between shapes (#8812)

Co-authored-by: dwelle <5153846+dwelle@users.noreply.github.com>

packages/excalidraw/scene/Scene.ts

@@ -25,6 +25,7 @@ import {
 import { arrayToMap } from "../utils";
 import { toBrandedType } from "../utils";
 import { ENV } from "../constants";
+import { getElementsInGroup } from "../groups";
 
 type ElementIdKey = InstanceType<typeof LinearElementEditor>["elementId"];
 type ElementKey = ExcalidrawElement | ElementIdKey;
@@ -437,6 +438,18 @@ class Scene {
     }
     return null;
   };
+
+  getElementsFromId = (id: string): ExcalidrawElement[] => {
+    const elementsMap = this.getNonDeletedElementsMap();
+    // first check if the id is an element
+    const el = elementsMap.get(id);
+    if (el) {
+      return [el];
+    }
+
+    // then, check if the id is a group
+    return getElementsInGroup(elementsMap, id);
+  };
 }
 
 export default Scene;