Refactor promo code handling in admin panel and clean up unused methods

- Replaced the promo_codes module with a new promo management structure, enhancing organization and clarity in the admin panel.
- Updated admin panel handlers to utilize the new promo management methods, improving the flow of promo code creation and management.
- Removed deprecated methods from payment and subscription data access layers, streamlining the codebase and improving maintainability.
- Ensured localization files are updated to reflect changes in promo management messaging, enhancing user experience.

db/dal/payment_dal.py

@@ -38,14 +38,6 @@ async def create_payment_record(session: AsyncSession,
     return new_payment
 
 
-async def get_payment_by_yookassa_id(
-        session: AsyncSession, yookassa_payment_id: str) -> Optional[Payment]:
-    stmt = select(Payment).where(
-        Payment.yookassa_payment_id == yookassa_payment_id)
-    result = await session.execute(stmt)
-    return result.scalar_one_or_none()
-
-
 async def get_payment_by_provider_payment_id(
         session: AsyncSession, provider_payment_id: str) -> Optional[Payment]:
     """Fetch a payment by provider-specific identifier."""
@@ -64,15 +56,6 @@ async def get_payment_by_db_id(session: AsyncSession,
     return result.scalar_one_or_none()
 
 
-async def get_payment_by_db_id_with_promo(
-        session: AsyncSession, payment_db_id: int) -> Optional[Payment]:
-
-    stmt = select(Payment).where(Payment.payment_id == payment_db_id).options(
-        selectinload(Payment.promo_code_used))
-    result = await session.execute(stmt)
-    return result.scalar_one_or_none()
-
-
 async def update_payment_status_by_db_id(
         session: AsyncSession,
         payment_db_id: int,
@@ -96,38 +79,6 @@ async def update_payment_status_by_db_id(
     return payment
 
 
-async def user_has_successful_payment_for_provider(
-        session: AsyncSession, user_id: int, provider: str) -> bool:
-    """Check if a user has at least one successful payment for the provider."""
-
-    stmt = (select(Payment.payment_id)
-            .where(Payment.user_id == user_id,
-                   Payment.provider == provider,
-                   Payment.status == 'succeeded')
-            .limit(1))
-    result = await session.execute(stmt)
-    return result.scalar_one_or_none() is not None
-
-
-async def update_payment_status_by_yk_id(session: AsyncSession,
-                                         yookassa_payment_id: str,
-                                         new_status: str) -> Optional[Payment]:
-    payment = await get_payment_by_yookassa_id(session, yookassa_payment_id)
-    if payment:
-        payment.status = new_status
-        payment.updated_at = func.now()
-        await session.flush()
-        await session.refresh(payment)
-        logging.info(
-            f"Payment record with YK ID {yookassa_payment_id} status updated to {new_status}."
-        )
-    else:
-        logging.warning(
-            f"Payment record with YK ID {yookassa_payment_id} not found for status update."
-        )
-    return payment
-
-
 async def get_recent_payment_logs_with_user(session: AsyncSession,
                                             limit: int = 20,
                                             offset: int = 0) -> List[Payment]: