Feature: #99191 - Create folders via modals

See forge#99191

Description

Creation of new folders in the File > Filelist module has been improved. Instead of a new window does the Create Folder button in the docheader, as well as the corresponding option in the context menu, now open a modal window, offering a form to create a folder. The modal window also contains the folder tree to select the parent folder. To allow editors creating folders sequentially, the modal is not automatically closed.

Impact

With the new modal window, backend users are able to create folders in an improved way, since they do not lose focus of the current view anymore. Additionally, the parent folder can easily be changed inside the modal window, which allows to create folders for different levels without leaving the form. After closing the modal window, the File > Filelist module does always automatically reload to instantly display the latest changes.