Add .avif (AV1 Image File Format) support
The AV1 Image File Format (AVIF) is a new image format based on the AV1 video codec. It would be great if support for this format could be added.
The AVIF spec can be found here: https://aomediacodec.github.io/av1-avif/
Netflix published a bunch of test images: http://download.opencontent.netflix.com/?prefix=AV1/Chimera/AVIF/