feat: Add option to flip single element on the context menu (#2520)

Co-authored-by: dwelle <luzar.david@gmail.com>

src/tests/helpers/ui.ts

@@ -6,6 +6,7 @@ import {
 import { CODES } from "../../keys";
 import { ToolName } from "../queries/toolQueries";
 import { fireEvent, GlobalTestState } from "../test-utils";
+import { mutateElement } from "../../element/mutateElement";
 import { API } from "./api";
 
 const { h } = window;
@@ -202,6 +203,7 @@ export class UI {
       size = 10,
       width = size,
       height = width,
+      angle = 0,
     }: {
       position?: number;
       x?: number;
@@ -209,6 +211,7 @@ export class UI {
       size?: number;
       width?: number;
       height?: number;
+      angle?: number;
     } = {},
   ): (T extends "arrow" | "line" | "draw"
     ? ExcalidrawLinearElement
@@ -231,6 +234,10 @@ export class UI {
 
     const origElement = h.elements[h.elements.length - 1] as any;
 
+    if (angle !== 0) {
+      mutateElement(origElement, { angle });
+    }
+
     return new Proxy(
       {},
       {