Convert Flipper plugin "mobileboost" to TypeScript

Summary: Bugfix for Tab.tsx + implicitly typed react vizualized

Reviewed By: danielbuechele

Differential Revision: D17205342

fbshipit-source-id: 48d29c583f0790af46f3d9c8d0280015b58d56aa

src/ui/components/Tab.tsx

@@ -38,6 +38,6 @@ export type Props = {
   width?: WidthProperty<number>;
 };
 
-export default function Tab(_props: Props) {
+export default function Tab(_props: Props): JSX.Element {
   throw new Error("don't render me");
 }