fix: source: MD Latest 3 Inch & 6 Inch Aerial Imagery (#2889)

* fix: source: MD Latest 3 Inch & 6 Inch Aerial Imagery

MD iMAP 3.0 ArcGIS Server Site has been Deprecated
* update paths to point to MD iMAP 4.0 ArcGIS Server
* update paths to icon assets, and other referenced pages
see https://mdgeodata.md.gov/Deprecation/

* fix: update geoJSON for MD_ThreeInchImagery source to reflect latest imagery

* fix: ring orientation for MD_ThreeInchImagery to comply with RFC7946

Author: naterkane