chore: re-split code editor

[ashtonG]

Ticket

none

Description

This fixes an issue where the code editor was being included in the main app bundle. While you can indicate that a component is meant to be split with React.lazy, if any code elsewhere imports the code statically the code is unsplit. We wrap the code split component and ban other imports using eslint to prevent this from regressing.

Test Plan

Frontend bundle size should be reduced. visiting places where the code editor is visible should show a spinner while the code editor is loading

Checklist

• [x] Changes have been manually QA'd
• [x] New features have been approved by the corresponding PM
• [x] User-facing API changes have the "User-facing API Change" label
• [x] Release notes have been added as a separate file under docs/release-notes/ See Release Note for details.
• [x] Licenses have been included for new code which was copied and/or modified from any external code