Separate EMZ/WMZ and SVGZ export support into different patches for readability: Add support for exporting EMZ/WMZ (patch <https://gerrit.libreoffice.org/c/core/+/135181>) Add support for exporting SVGZ (WIP) (patch <https://gerrit.libreoffice.org/c/core/+/135556/>)
Next: Finish SVGZ patch, start working on pngwriter if all goes well
