WIP: Decouple Features

- Separates Modal into CMS.Modal
- Separates Sideframe inti CMS.Sideframe
- Separates Clipboard into CMS.Clipboard
- Rename CMS.PlaceholderItem to CMS.Plugin
- Move tooltip, set/getSettings, preventScroll to CMS.Helpers
- Cleanup toolbar.html and introduce CMS.config