refactor(data-extraction): Move date_to_iso function to string_tools

tests/utils/string_tools_test.py

@@ -33,3 +33,15 @@ def test_simplify_string_type_error(value: Any) -> None:
     """Tests if the type error is thrown when the value is the wrong type."""
     with pytest.raises(TypeError):
         assert string_tools.simplify_string(value)
+
+
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    [
+        ("10.10.1111", "1111-10-10"),
+        ("10.10.98", "1998-10-10"),
+    ],
+)
+def test_transform_date_to_iso(value: str, expected: str) -> None:
+    result = string_tools.transform_date_to_iso(value)
+    assert result == expected