Fix linting errors

Fixing linting errors reported by eslint

frontend/src/routes/components/notFound.tsx

 import React from 'react'
-import { Page } from 'components/page'
+import Page from 'components/page'
 
 export default function NotFound() {
   return (
     <Page header="404 - Not found">
       <h2> 404 - Not found</h2>
     </Page>
   )