Drag-dropping a node in the same position and container no longer rem…

[StefanCodes]

The drag-drop apply function in its current form removes an element from its collection and then re-inserts it in its final place. This is normally fine, except when dragging and dropping a node into the same place. In this case, the node hasn't moved, but removing and reinserting the node can have side effects.

In my use case, we're using another library (BreezeJs) to perform automatic change detection. When dropping a node without moving, this causes simply clicking a draggable node to trigger change detection and improperly identify the node as changed.

This PR checks if the node is being dropped into the same container and index as it started in, and then returns without manipulating the node's place in its collection.

[Voles]

Thanks for your contribution! I've tested this locally, looking good. 👍