See nesting when drag-and-dropping requests

[ludwigschub]

Is your feature request related to a problem? Please describe.
I'm always frustrated when trying to drag and drop a request into a folder and not knowing whether the request is gonna land in or outside the folder when dropping the request (especially with new folders).

Bildschirmvideo.aufnehmen.2021-05-05.um.20.45.00.mov

Describe the solution you'd like
I'd like to:

• be able to drop it on the folder name to add it to the folder
• see the folder area color-highlighted when dropping it into the folder

Describe alternatives you've considered
Maybe one could also indent the bar that indicates the drop location.