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/InputButton.tsx

@@ -14,7 +14,7 @@ type InputButtonProps = {
   title?: string
 };
 
-export default class InputButton extends React.Component<InputButtonProps> {
+export class InputButton extends React.Component<InputButtonProps> {
   render() {
     return <button
       id={this.props.id}