CMS-3712 Reorganise api.ui classes

- moved buttons to api.ui.button
- moved responsive classess to api.ui.responsive
- moved masks to api.ui.mask
- moved uploader classes to api.ui.uploader
- moved panels to api.ui.panel
- moved inputs to api.ui.text
- renamed windows to panels and moved them to panel package
- also renamed styles and moved them to panel folder