Update polygons for grid-sources to be consistent with v8 catalogs

V8 catalogs extend catalog region (and use updated attenuation boundary). Adjust relevant polygon regions

Active-crust grid features:

• grid-system-active.geojson (already uses new atten boundary)

Stable-crust grid features:

• grid-system-stable.geojson (already uses new atten boundary)

Stable-crust grid features for consideration - updates to atten boundary. Consider making extensions at north and south ends of atten boundary consistent with the attached polygon-dev-catV8 files.

• USGS grid polygons: craton, default, and extended margin
• SSCN grid polygons: sscn-craton-1-9-10, sscn-default, sscn-gulf-coast-2-3