Fix backward compatibility of pull request 1722.

[robinechuca]

Same as 1722, keeping classical python set.

[WyattBlue]

The underlying principle for to_ndarray() is that bytes(to_ndarray(frame)) should be the same as the ffmpeg cli when returning the pix_fmt with -c:v rawvideo.

While I haven't checked this, I'm 90% sure that means putting the channel first in yuv444p16. I would like for the channel to be first in all relevant pix_fmts if the former condition holds. I'm okay with a channel_last parameter, but quite what you're doing.

Also more little things:

1. Don't put annotations in *.pyx, put then in the *.pyi files
2. Learn how to use feature branches in git so I don't have to "Squash and Merge" for your PRs in the future
3. Let's circle back to the skip_channel parm and the grb vs rgb thing when I'm happy with this PR, leave it out of this PR for now

[robinechuca]

Ha ok, I understand the logic now! This should be written in the to_ndarray documentation.
2. You mean you would like I work an an other branch than "main"?