move nshm to lib

src/hazard/src/main/java/gov/usgs/earthquake/nshmp/netcdf/Nshm.java → src/lib/src/main/java/gov/usgs/earthquake/nshmp/netcdf/Nshm.java

@@ -15,7 +15,8 @@ public enum Nshm {
     this.label = label;
   }
 
-  public String label() {
+  @Override
+  public String toString() {
     return label;
   }
 }