Refine and complete the new beta-tagged components #4060
Description
Currently the following features are new and still tagged with the [beta] label.
This includes:
- Collapsible
- Date Picker
- Listbox
- ToggleGroup
- TreeView
In most cases these components merely need some final design tweaks, as any notable issues have likely been filed and resolved by now.
Once these changes are complete, we should remove the tag and designate them stable for Skeleton v4.x