Make animated images also work with regular images

Currently an AnimatedImage doesn't show if you decide to load a regular image in it. (error: Reading ras files from sequential devices not supported)

It'd be great if it worked for both animated and non-animated images, a non-animated image would just have 1 frame.

That way you don't have to create both an AnimatedImage and an Image in your qml component and detect if the image loaded is animated and choose which to display.