Drag and Drop Rendering

`dnd_drag_source` provides a nice high level API which renders the draggable item near the mouse cursor while dragging. This fits my use case very well, but in my use case it would be ideal to also render the dragged item in the original location.

**Describe the solution you'd like**

I'd like to be able to configure `dnd_drag_source` to render the dragged item twice, once in its original location and once near the mouse cursor.

**Describe alternatives you've considered**

I believe this could be accomplished on top of the lower level drag and drop APIs, but that would require re-implementing rendering the dragged item near the mouse cursor.

Start by locating the implementation of `dnd_drag_source` and review the lower-level drag-and-drop APIs mentioned in the issue. Determine how the source item is rendered near the cursor and how its original location is handled. Done means the high-level API can be configured to render the dragged item both at its original location and near the cursor.

Written by the indexing model from the issue text.