Fix field query list types

[trombonehero]

When we use a field query to set a list, e.g.:

vendor_cxx_flags:list[string] = args.cxxflags ? [];

we currently get the error:

error: type error: expected list[nil], got list[string]
vendor_cxx_flags = args.cxxflags ? [];
                   ^~~~~~~~~~~~~~~~~~

We ought to use the expected type information to infer that the field (if it existed) would be a list[string].

[trombonehero]

This is blocking forward progress on the pegmatite branch.

[trombonehero]

This works in the new parsing and type model!