merge function
Merge creates one multi-channel array out of several single-channel ones.
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#ga7d7b4d6c6ee504b30a20b1680029c7b4
Implementation
Mat merge(VecMat mv, {OutputArray? dst}) {
final p = calloc<cvg.Mat>();
cvRun(() => cffi.Mat_Merge(mv.ref, p));
return Mat.fromPointer(p);
}