feat: implement billing system with Pally integration

- Added billing models and repository for handling bills.
- Introduced BillingService to manage payment initiation and bill creation.
- Updated user service to remove ticket-related functionality.
- Refactored settings to include new billing-related fields.
- Removed ticket-related handlers and schemas.
- Added new billing handlers for processing payments.
- Updated database schema with new bills table and status enum.
- Enhanced utility functions to calculate prices considering discounts.
- Introduced prehandling for non-private messages.
- Updated main application to initialize new billing services and repositories.

handlers/common.py

@@ -2,13 +2,12 @@ from aiogram import F, Router
 from aiogram.fsm.context import FSMContext
 from aiogram.types import CallbackQuery, Message
 
-from config import settings
 from texts import UNDEFINED_MESSAGE
 
 router = Router()
 
 
-@router.message(F.chat.id != settings.admin_group_id)
+@router.message()
 async def undefined_cmd(msg: Message):
     await msg.delete()
     await msg.answer(UNDEFINED_MESSAGE)