Add AVIF support

[zesky18]

I'm not sure if this is added yet so I'm going to leave it here for confirmation.

It is already possible to mokuro AVIF manga. Really the thing that doesn't support it is the Reader itself. It would be great to have this so we can switch to something more space efficient (which is also good for the Catalog since upscaled contributors can upload their manga faster).

[yuukibarns]

same here

[Galacktic]

truth nuke

[Gnathonic]

Support added. Waiting to merge in and deploy