feat: add support for wutta export-csv command

tests/cli/test_export_csv.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8; -*-
+
+from unittest import TestCase
+from unittest.mock import MagicMock, patch
+
+from wuttasync.cli import export_csv as mod, ImportCommandHandler
+
+
+class TestExportCsv(TestCase):
+
+    def test_basic(self):
+        params = {
+            "models": [],
+            "create": True,
+            "update": True,
+            "delete": False,
+            "dry_run": True,
+        }
+        ctx = MagicMock(params=params)
+        with patch.object(ImportCommandHandler, "run") as run:
+            mod.export_csv(ctx)
+            run.assert_called_once_with(ctx)