Add shields for unorganized territory roads in Minnesota

[1ec5]

In Minnesota, a county can establish a system of unorganized territory or unorganized township (UT) roads. At least two counties, Cook and St. Louis, have posted route markers for these roads: a white square with “UT” either toward the top or as a prefix of the route number. Following the usual pattern in Minnesota, network=US:MN:<county>:UT should result in a white rectangular shield. Since township roads and other types of county-maintained roads can also have white squares as shields, we need to add “UT” as a banner up top.

UT Road 9115 in Makinen Unorganized Territory, St. Louis County, Minnesota:

[StretchLongfellow]

Shoot, I was hoping we could just reuse a white square graphic.

Although given the other style, maybe that is still valid. If ref=UT ##, the UT will show and distinguish it.

[1ec5]

I don’t think the “UT” is an integral part of the route number in either case. It’s unlikely that anyone would refer to a Cook County UT road as, say, “UT Road UT 88”. We can probably get away with tagging the bare number in ref and using a plain white rectangle with the banner text on top.