Enhance private handlers structure and add database support

- Introduced a new `PrivateHandlers` class to encapsulate private message handling logic, improving organization and maintainability.
- Added new dependencies in `requirements.txt` for database support with `aiosqlite`.
- Updated the private handlers to utilize modular components for better separation of concerns and easier testing.
- Implemented error handling and logging for improved robustness in message processing.

helper_bot/handlers/private/decorators.py

@@ -0,0 +1,29 @@
+"""Decorators and utility functions for private handlers"""
+
+import traceback
+from aiogram import types
+from logs.custom_logger import logger
+
+
+def error_handler(func):
+    """Decorator for centralized error handling"""
+    async def wrapper(*args, **kwargs):
+        try:
+            return await func(*args, **kwargs)
+        except Exception as e:
+            logger.error(f"Error in {func.__name__}: {str(e)}")
+            # Try to send error to logs if possible
+            try:
+                message = next((arg for arg in args if isinstance(arg, types.Message)), None)
+                if message and hasattr(message, 'bot'):
+                    from helper_bot.utils.base_dependency_factory import get_global_instance
+                    bdf = get_global_instance()
+                    important_logs = bdf.settings['Telegram']['important_logs']
+                    await message.bot.send_message(
+                        chat_id=important_logs,
+                        text=f"Произошла ошибка в {func.__name__}: {str(e)}\n\nTraceback:\n{traceback.format_exc()}"
+                    )
+            except:
+                pass  # If we can't log the error, at least it was logged to logger
+            raise
+    return wrapper