Improve callbacks while zooming

[ofekudi]

Describe the bug
There are two main problems:

1. The callback for onCropComplete is being called repeatedly while zooming - so they are being simultaneously called
2. While zooming, the onZoomChange is being called a lot of times (maybe it's possible to throttle it)

To Reproduce
Steps to reproduce the behavior:

1. Add logs in the onCropComplete and onZoomChange callbacks
2. Zoom in

Expected behavior

1. onCropComplete will be called only once - after you finish zooming (the same behavior as happens with onCropChange)
2. onZoomChange will be called less frequently

Here's a sample of the logs while zooming in:

Thanks for your help! This package is super useful!