Refactor bot handlers and keyboards; implement admin features

- Removed unused prehandling, referrals, support, and states files.
- Updated admin and client handlers to improve structure and functionality.
- Introduced admin filters and routers for better access control.
- Added new billing and deposit functionalities for client interactions.
- Enhanced keyboard layouts for admin and client menus.
- Implemented promotion handling for admin users.
- Updated configuration to include admin settings.
- Improved utility functions for quote fetching and menu text building.
- Added common handlers for undefined commands and message deletions.

schemas/promotions.py

@@ -5,5 +5,5 @@ from aiogram.types import Message
 
 @dataclass
 class NewPromotionContext:
-    creator_id: int
-    message: Message | None = None
+    msg: Message
+    promotion: Message | None = None