Improve usability when selecting roles and folders for user accounts

'Current Situation

• When assigning roles to a user account then the list of roles and folders is displayed
• An administrator has to select both a folder and a role.
• The user interface does not visually distinguish between folders and roles.

Desired Behavior

• The GUI should visually distinguish between folders and roles.
• It should be evident for an administrator that for a folder a role has to be selected.