Migrate mature functions from carpenter_workshop into Herbie

[blaylockbk]

I've dumped several useful tools I've developed and use regularly in my Carpenter_Workshop repository. That has been one of my sandbox areas. Some of those I use so much, I might even classify them as "mature" features. Maybe it's time to put them in the Herbie repo.

• EasyMap, for making Cartopy basemaps easier.
• Paint, specifically the NWS standard colormaps for temperature/wind/etc. (these need some work to implement the right way)
• Wind unit converters for wind speed/direction, longitude to_180 and t0_360