[Feature] PNG quality & size optimisation

[lastbattle]

When exporting images from WZ, include the surface format in the metadata of the png.

When importing an external PNG, HaRepacker has to decide the types of surface format that the image should be based on its ARGB bytes signature (dxt3, dxt5, Bgr565, or Bgra4444) if its not available.
Then compresses it accordingly before storing it into WZ. (WzPngProperty format+format2 is currently not well handled)