Could add the support to save BigTIFF directly?

[JiangXL]

FileIO.jl can load BigTIFF, but fail to save it. convert -list format shows the ability to save as BigTIFF.

cd .julia/packages/ImageMagick/vMfoS/deps/usr/bin
./convert -list format
     TIFF* rw+   Tagged Image File Format (LIBTIFF, Version 4.0.9)
   TIFF64* rw-   Tagged Image File Format (64-bit) (LIBTIFF, Version 4.0.9)

So, how can ImageMagick.jl do save(File(format"TIFF64","result.tiff"), img as ImageMagick do convert input.tiff TIFF64:result.tiff?

Thanks!