Line + label style for a spatial unit type
Arguments
- zone_type
character(1): programarea, planarea (v1's analogue of the
Program Areas), ecoregion, subregion, or anything else (which gets the muted
context style)
Value
list with line (color, width, opacity, dasharray or NULL) and
label (color, size, halo_color, halo_width), where label is NULL
for a unit drawn without labels