Support setting bounds when dragged element is bigger than the parent

[David Han]

The bounds param breaks short in use cases where the dragged element is bigger than the parent.
For example, imagine a pannable graph of 1000 x 1000 pixels shown in a viewport of 400 x 400 pixels. Here, the bounds = 'parent' bricks the entire draggable, because mathematically, at least one side must be out of bounds.

Suggestions:

Support something like DragBounds but where the bounds are relative to the parent's local coordinates instead of the window.

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Also, a way to easily implement overscroll would be great.

Thanks!