cleanup Lens repo with tighter linting

Signed-off-by: Sebastian Malton <smalton@mirantis.com>

dashboard/client/components/+404/index.ts

@@ -1 +1 @@
-export * from "./not-found"
+export * from "./not-found";

dashboard/client/components/+404/not-found.tsx

@@ -3,13 +3,13 @@ import { Trans } from "@lingui/macro";
 import { MainLayout } from "../layout/main-layout";
 
 export class NotFound extends React.Component {
-  render() {
+  render(): JSX.Element {
     return (
       <MainLayout className="NotFound" contentClass="flex" footer={null}>
         <p className="box center">
           <Trans>Page not found</Trans>
         </p>
       </MainLayout>
-    )
+    );
   }
 }