D8598: WIP: position files at drop target position in folder

[Milian Wolff]

mwolff added a reviewer: amantia.

REPOSITORY
  R119 Plasma Desktop

REVISION DETAIL
  https://phabricator.kde.org/D8598

To: mwolff, hein, amantia
Cc: plasma-devel, ZrenBot, progwolff, lesliezhai, ali-mohamed, jensreuterberg, 
abetts, sebas, apol, mart