change export file configuration to be compliant with new sandpiper sandsuet specification

[amoodie]

The sandsuet v1.0 data specification is released. This is a great format for the ouput of the pydeltarcm gridded data.

Reformat the data output from pydeltarcm to be compliant with the new sandsuet data specification. this will require a version change, as it is a breaking change.

[amoodie]

a script used to convert an old model output to a sandsuet dataset will be a helpful starting point

sandsuet_reprocess_golf.py