Replace default export with named exports (#1998)

## Launch Checklist

See title,
Also removed some "_" from some file names.
This is a pure refactoring, no logic changes.


 - [x] Briefly describe the changes in this PR.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/components/AppLayout.tsx

@@ -1,5 +1,5 @@
 import React from "react";
-import ScrollContainer from "./ScrollContainer";
+import { ScrollContainer } from "./ScrollContainer";
 import { type WithTranslation, withTranslation } from "react-i18next";
 import { IconContext } from "react-icons";
 
@@ -50,5 +50,4 @@ class AppLayoutInternal extends React.Component<AppLayoutInternalProps> {
   }
 }
 
-const AppLayout = withTranslation()(AppLayoutInternal);
-export default AppLayout;
+export const AppLayout = withTranslation()(AppLayoutInternal);