Interactable: fix dropChecker method
Rename 'dropRect' to just 'rect'

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Allow changing of the function to calculate rect

Interactable#rectChecker() returns or sets the getRect method of the
Interactable. Interactable#getRect should return an object with top,
left, right, bottom, width and height of the interctable's element.
Move getAction from IOptions to Interactable