Support for JPEGXL

[sagudev]

https://caniuse.com/jpegxl

We could use https://github.com/tirr-c/jxl-oxide for our implementation.

[Quackdoc]

when testing the PR for integration of jxl-oxide image-rs, I did have a demo working with servo, but JXL has been rejected from image-rs until an open spec is availible so that's not an option. There has been talk of making an "image-rs" compatible API for jxl-oxide (right now it's a nice to have but low priority). That seems like it may help support this a bit better?

It might be relevant when working on image handling to keep image-rs/image#1979 in mind.