add mailing function

app/bot/dialogs/flows/mailing/states.py

@@ -0,0 +1,8 @@
+from aiogram.fsm.state import State, StatesGroup
+
+
+class MailingSG(StatesGroup):
+    message_data = State()
+    recipients = State()
+    # mailing_date = State()
+    confirm = State()