Refactor WorkflowContentsManager to use a list for tags instead of a string

        If `allow_upgrade`, the workflow and sub-workflows might use updated tool versions when refactoring.

        """

        annotation_str = ""

        tag_str = ""

        tags_list = []

        annotation_owner = None

        if stored is not None:

            if stored.id:

                    or self.get_item_annotation_str(trans.sa_session, annotation_owner, stored)

                    or ""

                )

                tag_str = stored.make_tag_string_list()

                tags_list = stored.make_tag_string_list()

            else:

                # dry run with flushed workflow objects, just use the annotation

                annotations = stored.annotations

        data["format-version"] = "0.1"

        data["name"] = workflow.name

        data["annotation"] = annotation_str

        data["tags"] = tag_str

        data["tags"] = tags_list

        if workflow.uuid is not None:

            data["uuid"] = str(workflow.uuid)

        steps: Dict[int, Dict[str, Any]] = {}