fix typo CommonResults (#129)

Author: cbellot000

ansys/dpf/core/results.py

@@ -649,7 +649,7 @@ def stress(self):
         >>> stress = stress.on_last_time_freq.on_named_selection("_CONSTRAINEDNODES")
         >>> last_time_disp = stress.eval()
         """
-        return super().__result__("elastic_strain")
+        return super().__result__("stress")
 
     @property
     def structural_temperature(self):

tests/test_model.py

@@ -206,6 +206,7 @@ def test_result_not_dynamic(plate_msup):
     assert np.allclose(
         fc.time_freq_support.time_frequencies.data, np.array([0.115, 0.125])
     )
+    assert fc[0].unit == "Pa"
     dis = model.results.displacement().eval()
     dpf.core.settings.set_dynamic_available_results_capability(True)