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/utils/logging.py

@@ -0,0 +1,17 @@
+"""Logging configuration for log-alert application."""
+
+import logging
+import os
+
+
+def setup_logging():
+    """Configure root logger for the application."""
+    logging.basicConfig(
+        level=os.environ.get("LOGLEVEL", "INFO"),
+        format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+    )
+
+
+def get_logger(name: str) -> logging.Logger:
+    """Get a logger instance with the given name."""
+    return logging.getLogger(name)