Correctly make Zip type following work

[gordonwatts]

The Zip predicate can be used in various places in an uproot call:

def test_dictionary_Zip_key():
    "Check that type follow from a dictionary through a Zip works"

    s = ast_lambda(
        """({
        'jet_pt':  e.Jets().Select(lambda j: j.pt()),
        'jet_eta': e.Jets().Select(lambda j: j.eta())}
        .Zip()
        .Select(lambda j: j.pt()))"""
    )
    objs = ObjectStream[Event](ast.Name(id="e", ctx=ast.Load()))

    new_objs, new_s, expr_type = remap_by_types(objs, "e", Event, s)

    assert expr_type == Any

Here it is taking a dictionary of two List[float]'s and turning it into a List[Dict[str, float]] - or, rather, internally, as the temp dataclass that a dict becomes.

The code for Zip to type follow should be added. It would have to be added in the process_method_call code, and probably some reasonably major surgery would be needed here.