Stateless ncwms get filters as json

 * Stateless `getFiltersAsJSON controller for ncwms
 * Stateless `getStylesAsJSON controller for ncwms
 * Client parsing is now much dumber
 * Date assembly is done in server side (grails)
 * Fix NcWMS GFI

This API is still work in progress, but enables us to see where we actually want to get to.
Already fixed, will come in the next PR with the async stuff. Was a pretty easy fix.