Add optional support for JPEG-LS, JPEG and JPEG2000 transfer syntaxes

[segmed-lam]

This PR adds logic to parse pixel data using CharLS/OpenJPEG/DCMTK if it can be imported. Tested on some compressed MR, CT and X-ray data.

[suyashkumar]

@segmed-lam thanks for putting this together! I'll carve out some time to take a closer look this week. Out of curiosity, have you had a chance to play around with the native Go JPEG-LS decoder that popped up recently? https://github.com/jamesshenjian/jpegsl/tree/main (at least for JPEG-LS, not sure if this will work for JPEG2000 and other formats)? I think it could use a lot of improvements still, and I do like the idea of being able to register custom decoder logic as you've put together here.

I also didn't check carefully, but it does seem like you did your best to keep the cgo deps factored out to a separate package, so hopefully this means we can avoid cgo deps by default for most people building this, but need to check more into that.

[segmed-lam]

@suyashkumar

Out of curiosity, have you had a chance to play around with the native Go JPEG-LS decoder that popped up recently?

Yes, I did, but it couldn't decode the test JPEG-LS image. No error message is displayed, so I can't tell what the issue is.

I also didn't check carefully, but it does seem like you did your best to keep the cgo deps factored out to a separate package, so hopefully this means we can avoid cgo deps by default for most people building this, but need to check more into that.

You're right.