* chore(dragging): Rename core/interfaces/i_draggable.ts
Rename core/interfaces/i_draggable.ts to
core/interfaces/i_draggable.old.ts to make room for new
IDraggable. Do not rename actual interface as it's not yet
clear that it will be necessary for both to coexist as
imports in the same file.
* feat(dragging): Introduce new IDraggable interface
* feat(dragging): Introduce new IDragger interface
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Co-authored-by: Beka Westberg <bwestberg@google.com>