extra_drag_dest_targets
Description:
Extra drag destination targets.
Allows to drag arbitrary content onto tabs, for example URLs in a web browser.
If a tab is hovered for a certain period of time while dragging the content, it will be automatically selected.
After content is dropped, the [signal@TabBar:HdyTabBar:extra-drag-data-received] signal can be used to retrieve and process the
drag data.