Drag and drop data value into variant

[Dataflow_G]

There are cases where a variant constant / control needs to have a data value. This can be done by right-clicking a control / constant, selecting Data Operations -> Copy Data, then right-clicking the variant and selecting Data Operations -> Paste Data. This can be time consuming for many variants.

The idea is to allow dragging and dropping of a control or constant onto a variant, and have the data copied to the variant:

[wiebe@CARYA]

Didn't even know about the copy\paste! Dragging\dropping would be even better.