Add Godiva properties to WMS config

[tdrwenski]

Suggestion from: Reading-eScience-Centre/edal-java#163 (comment)

it would also be useful to allow the configuration of the Godiva3 viewer in TDS. In the standard ncWMS2/EDAL, this can be done using the godiva3.properties as described here under the "Configuring Godiva3" topic.
One benefit from this would be to allow a TDS admin to set up a different base layer in Godiva3 (from OpenStreetMap, Stamen, Esri, local GeoServer, etc). This way, if there was a problem with the default base layer access (hosted on a Reading server), a different layer could be used.