Service model metadata

• Restructure dynamic services that rely on NSHM models to get necessary metadata on supported site classes (Vs30) and IMTs from loaded model. With container based models there is no reason to suppress models from loading.
• Refactor BaseModel away in favor Model; merge CEUS and WUS models into CONUS models.

changed title from Service model metadata 1 to Service model metadata

changed the description

Consolidated into #443 (closed)

closed