Refactor LayerUI (#1434)

* chore(gitignore): add .idea to gitignore

* refactor(layerui): pass named function to react.memo so that in dev tools the name shows up

This makes debugging easier as well

* refactor(layerui): break the functional component into multiple render methods

src/components/App.tsx

@@ -114,7 +114,7 @@ import {
   TAP_TWICE_TIMEOUT,
 } from "../time_constants";
 
-import { LayerUI } from "./LayerUI";
+import LayerUI from "./LayerUI";
 import { ScrollBars, SceneState } from "../scene/types";
 import { generateCollaborationLink, getCollaborationLinkData } from "../data";
 import { mutateElement, newElementWith } from "../element/mutateElement";