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/ScrollContainer.tsx

@@ -4,7 +4,7 @@ type ScrollContainerProps = {
   children?: React.ReactNode
 };
 
-export default class ScrollContainer extends React.Component<ScrollContainerProps> {
+export class ScrollContainer extends React.Component<ScrollContainerProps> {
   render() {
     return <div className="maputnik-scroll-container">
       {this.props.children}