Add new Feature: onLoadEnd() event as props

[emmanuel-D]

Currently there is no props for handling onLoadEnd event, when the image has been totally loaded from a server. I personally need that props to handle a function. It would be a nice feature for this cool component 😉.

[emmanuel-D]

@ArtemKolichenkov Is there any update about my issue ?

[ArtemKolichenkov]

@emmanuel-D I'm a bit more focused on the underlying https://github.com/ascoders/react-native-image-zoom package now. I'll start addressing current repo's issues a bit later, sorry. But yeah, this ehancement seems logical, will put it high on the TODO list.