Add USGS NAIP Plus layer to replace decommissioned layers

[emxsys]

Add the USGS NAIP Plus layer to the default layer list as a replacement for both the USDA NAIP USGS layer and the internal hosted USDA NAIP layer. USGS NAIP Plus is also the recommended replacement for the recently decommissioned USGS EROS Ortho NAIP layer.

See: https://www.usgs.gov/news/usgs-national-map-orthoimagery-map-services-transition-and-other-map-service-changes

[emxsys]

NAIP Plus Service Description: The USGS NAIP Plus service from The National Map consists of National Agriculture Imagery Program (NAIP) and high resolution orthoimagery (HRO) that combine the visual attributes of an aerial photograph with the spatial accuracy and reliability of a map. Digital orthoimage resolution may vary from 6 inches to 1 meter. In the former resolution, every pixel in an orthoimage covers a six inch square of the earth’s surface, while in the latter resolution, each pixel represents a one meter square. Many states contribute orthoimagery to The National Map, and the USGS also relies on a partnership with the U.S. Department of Agriculture's Farm Service Agency. The National Map download client allows free downloads of public domain, 1-meter resolution orthoimagery in JPEG 2000 (jp2) format for the conterminous United States, with many urban areas and other locations at 1-foot (or better) resolution also in JPEG 2000 (jp2) format. For additional information on imagery products, go to https://lta.cr.usgs.gov/node/300 and https://lta.cr.usgs.gov/high_res_ortho/.

[emxsys]

Added the USDA NAIP Layer from The National Map to the default layer list. This layer has orthoimagery coverage for the US and its outlying properties with up to 0.5m per pixel resolution.

This layer is a replacement for the deprecated USDA NAIP and USDA NAIP USGS layers and it is the recommend replacement for the decommissioned USGS Digital Ortho and USGS Urban Area Ortho layers. The XML config files for the deprecated and/or decommissioned layers have be marked as DEPRECATED via comments in the XML. These config files remain in the config/Earth folder to support clients that have existing disk caches supporting these layers.