v2.2.9: Refactors SectionTrait for better group handling

Refactors SectionTrait to improve section and group management within forms.

- Simplifies group instantiation by using the `ControlGroup` class directly.
- Renames the redraw handler to prevent naming collisions.
- Improves section retrieval by checking for `ControlGroup` instances instead of relying on a string `type` property.