Add middleware and refactor admin handlers for improved functionality

- Introduced `DependenciesMiddleware` and `BlacklistMiddleware` for enhanced request handling across all routers.
- Refactored admin handlers to utilize new middleware, improving access control and error handling.
- Updated the `admin_router` to include middleware for access checks and streamlined the process of banning users.
- Enhanced the structure of admin handler imports for better organization and maintainability.
- Improved error handling in various admin functions to ensure robust user interactions.

helper_bot/handlers/private/__init__.py

@@ -1,20 +1,45 @@
 """Private handlers package for Telegram bot"""
 
-from .private_handlers import private_router, create_private_handlers, PrivateHandlers
-from .services import BotSettings, UserService, PostService, StickerService
-from .constants import FSM_STATES, BUTTON_TEXTS, ERROR_MESSAGES
+# Local imports - main components
+from .private_handlers import (
+    private_router, 
+    create_private_handlers, 
+    PrivateHandlers
+)
+
+# Local imports - services
+from .services import (
+    BotSettings, 
+    UserService, 
+    PostService, 
+    StickerService
+)
+
+# Local imports - constants and utilities
+from .constants import (
+    FSM_STATES, 
+    BUTTON_TEXTS, 
+    ERROR_MESSAGES
+)
 from .decorators import error_handler
 
 __all__ = [
+    # Main components
     'private_router',
     'create_private_handlers', 
     'PrivateHandlers',
+    
+    # Services
     'BotSettings',
     'UserService',
     'PostService', 
     'StickerService',
+    
+    # Constants
     'FSM_STATES',
     'BUTTON_TEXTS',
     'ERROR_MESSAGES',
+    
+    # Utilities
     'error_handler'
 ]