New finalScalePosition Param

[LiamBateman]

When we use the onPinchEnd event as so:

onPinchEnd={(e) => console.log('onPinchEnd', e)}

It returns only the scale change, not the new scale. I propose to include another parameter which returns the current scale as well.

This is super useful for matching other UI elements that may need to move in time with the image being scaled.

I've proposed the name 'finalScalePosition'.

(#83)

[likashefqet]

PR looks fine, although I would suggest passing an animated scale value as a prop to the ImageZoom/Zoomable component for smoother animations that update in real time instead of waiting for the gesture to end. This value will reflect the component’s current scale and can be used to drive animations of other elements seamlessly during gestures.