External type defined in UDL can't be referenced in record defined by a procmacro

[mhammond]

In our ext-types fixture we import a type named UniffiOneInterface which is defined via UDL in another crate

While that crate works, it fails if that same crate tries to refer to that type in a dictionary defined by a procmacro, eg:

#[derive(Default, uniffi::Record)]
pub struct ObjectsType {
    pub maybe_interface: Option<Arc<UniffiOneInterface>>,
}

fails with:

thread 'uniffi_foreign_language_testcase_test_imported_types_swift' panicked at 'assertion failed: `(left == right)`
  left: `External { module_path: "uniffi_one", name: "UniffiOneInterface", namespace: "uniffi_one_ns", kind: Interface, tagged: false }`,
 right: `External { module_path: "uniffi_one", name: "UniffiOneInterface", namespace: "uniffi_one_ns", kind: Interface, tagged: true }`', uniffi_bindgen/src/interface/universe.rs:49:17

The problem is that things get confused about whether the external type is tagged or not. This is another example of where having some types be tagged and others not causes problems.