test: fix failing tests and API (#5823)

* tests: fix failing tests

* fix selection.test.tsx

* fix excalidraw.test.tsx and don't show image export when SaveAsImage is false in UIOptions.canvasActions

* more fixes

* require fake index db in setUp test to fix the tests

* fix regression

src/setupTests.ts

@@ -3,6 +3,8 @@ import "jest-canvas-mock";
 import dotenv from "dotenv";
 import polyfill from "./polyfill";
 
+require("fake-indexeddb/auto");
+
 polyfill();
 // jest doesn't know of .env.development so we need to init it ourselves
 dotenv.config({