`OutputFormat` and `Delivery` enums do not make logical sense

[gordonwatts]

In the following code:

    spec = sx.ServiceXSpec(
        General=sx.General(
            ServiceX="atlasr22",
            Codegen=query[1],
            OutputFormat=sx.ResultFormat.root,  # type: ignore
            Delivery=("LocalCache" if download else "SignedURLs"),  # type: ignore
        ),

The OutputFormat and Delivery can be enums. However, they need to be "normalized":

• The definition for OutputFormat uses OutputFormatEnum as its enum. However, code I've encountered uses ResultFormat, which is defined in a different place. And the two have seeminly identical definitions.

• Same for Delivery (though that isn't defined in models.py)

• The actual enums for this are really hard to figure out how to import.

It would be good if all of these enum's could be normalized, and importing them could be done in a straight forward way (currently deliver is at the top level import in servicex, but these enums are very deep)