Walks the repo and returns work items.

def get_all_items(self):
        """Walks the repo and returns work items."""
        for item in os.walk(self.test_case_dir):
            if "workitem.xml" not in item[2]:
                continue
            case_id = os.path.split(item[0])[-1]
            if not (case_id and "*" not in case_id):
                continue
            item_cache = self[case_id]
            if not item_cache:
                continue
            if not item_cache.get("title"):
                continue
            yield item_cache