chore(ui): migrate more code to typescript

ui/src/Components/CenteredMessage/index.tsx

@@ -1,10 +1,13 @@
-import React from "react";
+import React, { FC, ReactNode } from "react";
 
 import { CSSTransition } from "react-transition-group";
 
 import { ThemeContext } from "Components/Theme";
 
-const CenteredMessage = ({ children, className }) => {
+const CenteredMessage: FC<{
+  children: ReactNode;
+  className: string;
+}> = ({ children, className }) => {
   const context = React.useContext(ThemeContext);
   return (
     <CSSTransition