feat(process_label): add process role labeling for PostgreSQL connections

- Introduced a new module to determine the process role based on command-line arguments, enhancing PostgreSQL connection labeling for better monitoring.
- Updated the database connection parameters to include the application name derived from the process role.
- Added unit tests to validate the process role detection logic for different scenarios, including Celery and uWSGI.

tests/test_process_label.py

@@ -0,0 +1,18 @@
+from unittest.mock import patch
+
+from django.test import SimpleTestCase
+
+from dispatcharr.db.process_label import get_process_role
+
+
+class ProcessLabelTests(SimpleTestCase):
+    def test_celery_worker_not_labeled_as_uwsgi(self):
+        role = get_process_role(
+            ["/dispatcharrpy/bin/celery", "-A", "dispatcharr", "worker"]
+        )
+        self.assertEqual(role, "celery-worker")
+
+    def test_uwsgi_labeled_when_gevent_support(self):
+        with patch.dict("os.environ", {"GEVENT_SUPPORT": "True"}):
+            role = get_process_role(["uwsgi"])
+        self.assertEqual(role, "uwsgi")