Add field enum to aid in querying

[jdimeo]

Is it possible to add an enum to the type template with all the field names? This helps when you have to refer to a field by name and aren't using the getter/setter accessors. I think this would be useful when building queries to know that you don't have any typos.

Is there another way of doing this that I'm missing?

Here's a simple implementation but I don't know ST4 enough to know the right way of omitting the comma on the last enum item:
5a87dd9

Happy to open a PR from my fork if this would be helpful