RFE: CN.isLockOrientation

[jsfan3]

I would suggest, after implementing the RFE https://github.com/codenameone/CodenameOne/issues/3209, to add a CN.isLockOrientation() API. The reason is that a cn1lib may need to lock the screen, but before doing so it should know whether it is already locked or not (and in which orientation), so it consistently follows a certain logic rather than another. This is the case with cn1lib PhotoCropper, as discussed here: https://github.com/javieranton-zz/PhotoCropper/issues/1#issuecomment-671041823