New class to handle JPEG-XR images

[piponazo]

#1919 added preliminary support for JPEG-XR images.

As it was pointed out in that PR, we should probably take this out to a proper new format and source file, like the other TIFF-derived formats (see ORF, RW2), rather than just simply piggy-backing TIFF base classes.

Chances are that there might be more to JPEG-XR the container than just the header difference.

[kmilos]

See https://www.itu.int/rec/T-REC-T.832-201906-I/en and also https://www.loc.gov/preservation/digital/formats/content/tiff_tags.shtml

There are "HD Photo" (i.e. JPEG XR) tags like ImageWidth/ImageHeight that are duplicated/conflict w/ regular TIFF tags. Maybe the workaround would be to rename them to e.g. TransformedImageWidth and still keep it as a TIFF. In any case, it would be good to comb through the spec.