feat(agora): add decorators file

src/agora/io/decorators.py

+#!/usr/bin/env jupyter
+"""
+Convenience decorators that extend commonly-used methods or functions.
+"""
+import typing as t
+from functools import wraps
+
+
+def _first_arg_str_to_df(
+    fn: t.Callable,
+):
+    """Ensures Signal-like classes convert strings to datasets when calling them"""
+
+    @wraps(fn)
+    def format_input(*args, **kwargs):
+        cls = args[0]
+        data = args[1]
+        if isinstance(data, str):
+            data = cls.get_raw(data)
+        return fn(cls, data, *args[2:], **kwargs)
+
+    return format_input