fix: Elbow arrow fixedpoint flipping now properly flips on inverted resize and flip action (#8324)

* Flipping action now properly mirrors selections with elbow arrows
* Flipping action now re-centers the selection to the original center to avoid "walking" selections on repeated flipping

packages/excalidraw/tests/helpers/api.ts

@@ -9,6 +9,8 @@ import type {
   ExcalidrawFrameElement,
   ExcalidrawElementType,
   ExcalidrawMagicFrameElement,
+  ExcalidrawElbowArrowElement,
+  ExcalidrawArrowElement,
 } from "../../element/types";
 import { newElement, newTextElement, newLinearElement } from "../../element";
 import { DEFAULT_VERTICAL_ALIGN, ROUNDNESS } from "../../constants";
@@ -179,10 +181,10 @@ export class API {
     scale?: T extends "image" ? ExcalidrawImageElement["scale"] : never;
     status?: T extends "image" ? ExcalidrawImageElement["status"] : never;
     startBinding?: T extends "arrow"
-      ? ExcalidrawLinearElement["startBinding"]
+      ? ExcalidrawArrowElement["startBinding"] | ExcalidrawElbowArrowElement["startBinding"]
       : never;
     endBinding?: T extends "arrow"
-      ? ExcalidrawLinearElement["endBinding"]
+      ? ExcalidrawArrowElement["endBinding"] | ExcalidrawElbowArrowElement["endBinding"]
       : never;
     elbowed?: boolean;
   }): T extends "arrow" | "line"