🤡(app-impress) mock BlockNoteEditor

BlockNoteEditor uses many libraries not compatible
with Jest.
This commit mocks the BlockNoteEditor
component to allow Jest to run without errors.

src/frontend/apps/impress/jest/mocks/ComponentMock.js

@@ -0,0 +1,5 @@
+import React from 'react';
+
+export const ComponentMock = () => {
+  return <div>My component mocked</div>;
+};