webui: Add editing attachments in user messages (#18147)
* feat: Enable editing attachments in user messages
* feat: Improvements for data handling & UI
* docs: Update Architecture diagrams
* chore: update webui build output
* refactor: Exports
* chore: update webui build output
* feat: Add handling paste for Chat Message Edit Form
* chore: update webui build output
* refactor: Cleanup
* chore: update webui build output
