Make geoPDFs prettier

[jforthofer]

To make them look better, we could:

• maybe shrink the legend and icons a bit more
• make the TopoFire icon the same size (vertically) as the WindNinja icon
• add a bit of white space buffer around the legend and icons so they don't go to the edge of the paper or touch the map
• move the legend and icons horizontally so they line up (if possible) with the east and west edge of the map, not possible for very narrow maps
• add date time text somewhere if this is a wx model run
• add a scale bar and magnetic declination image like CalTopo
• make the hillshade a true hillshade