Calculation and service validation improvements

• Currently older GMMs that only support vs30=[760, 2000] throw server side errors when a different vs30 is selected. Need to determine if graceful failure is handled on the client or server.
• Dynamic UHT calculations return results outside the bounds where static curves are calculated and can therefore give a very incomplete hazard results for sites (e.g. northwest Bahamas) towards the edges of our rectangular/mercator map regions.
• Handle out of range deagg return periods and IMLs