SIENTIAPDE-1445

Invert startTime and endTime parameters in PIWebAPIClient to ensure descending order results. Update tests to verify parameter handling and use pytest.approx for floating-point comparisons.

tests/activities/test_api.py

@@ -146,7 +146,7 @@ async def test_get_tag_values_success(api_activity):
 
     assert len(result) == 3
     assert result[0]['name'] == 'tag1'
-    assert result[0]['value'] == 10.5
+    assert result[0]['value'] == pytest.approx(10.5)
     assert result[1]['name'] == 'tag2'
     assert result[2]['name'] == 'tag3'
     assert result[0]['timestamp'] == '2023-01-01 12:02:00+0000'
@@ -332,6 +332,6 @@ async def test_get_tag_values_with_nan_values(api_activity):
 
     # Verify
     assert len(result) == 2
-    assert result[0]['value'] == 10.0
+    assert result[0]['value'] == pytest.approx(10.0)
     # NaN should be preserved in the result
     assert pd.isna(result[1]['value'])