feat: Refactor log-alert application into modular structure

- Introduced alerters package with base Alerter class and implementations for LogAlerter and GotifyAlerter.
- Created fetchers package with abstract LogFetcher class and implementations for FileLogFetcher, LokiLogFetcher, and ParseableLogFetcher.
- Added filters package with base Filter class and implementations for RegexpFilter and GeolocationFilter.
- Implemented rules package with base AlertRule class and SimpleAlertRule for alerting logic.
- Enhanced configuration handling with utilities for loading and validating JSON configuration.
- Updated logging setup for better logging management.
- Modified main application logic to utilize the new modular structure, improving maintainability and readability.
- Updated config.json and config.schema.json to reflect changes in alerting and fetching configurations.
- Added python-dateutil to requirements for date parsing functionality.

log-alert/fetchers/base.py

@@ -0,0 +1,36 @@
+"""Abstract base class for log fetchers."""
+
+from abc import ABC, abstractmethod
+from typing import Dict, Any, List
+
+
+class LogFetcher(ABC):
+    """Abstract base class for log fetchers."""
+
+    """Fetch logs."""
+    @abstractmethod
+    def fetch_logs(self, filters: Dict[str, Any]) -> List[Dict[str, Any]]:
+        """Fetch logs within the specified time range.
+        
+        Args:
+            filters: Dictionary of filters to apply
+            
+        Returns:
+            List of log entries
+        """
+        pass
+
+    """ Fetch logs with time range."""
+    @abstractmethod
+    def fetch_logs_time_range(self, filters: Dict[str, Any], start_time: int, end_time: int) -> List[Dict[str, Any]]:
+        """Fetch logs within the specified time range.
+        
+        Args:
+            filters: Dictionary of filters to apply
+            start_time: Start time in seconds since epoch
+            end_time: End time in seconds since epoch
+            
+        Returns:
+            List of log entries
+        """
+        pass