qt: use `text/uri-list` for internal dragging instead of input items
We already handle text/uri-list
, since we support dragging from
external sources. However, internally, this route is not used and
rather input items are considered for dragging.
This change does not affect internal intra-view move, but affects inter-view insertion.
This also makes it possible to drag media library items that are collection of media outside the application.
Based on !5899 (merged).
Edited by Fatih Uzunoğlu