fix(FXC-6541): fix failing tests and improve type annotations

- Update translator input data files to use null for default surface
  output name, matching the new None default
- Regenerate service_init ref files from current model defaults
- Fix surface_output_class type annotations to use Type[] instead of
  instance types

Made-with: Cursor

Author: NasserFlexCompute

flow360/component/simulation/translator/solver_translator.py

@@ -545,7 +545,7 @@ def translate_volume_output(
 
 def translate_imported_surface_output(
     output_params: list,
-    surface_output_class: Union[SurfaceOutput, TimeAverageSurfaceOutput],
+    surface_output_class: Union[Type[SurfaceOutput], Type[TimeAverageSurfaceOutput]],
     coordinate_system_manager=None,
 ):
     """Translate imported surface output settings."""
@@ -570,7 +570,7 @@ def translate_imported_surface_output(
 
 def _translate_single_surface_output(
     output_instance,
-    surface_output_class: Union[SurfaceOutput, TimeAverageSurfaceOutput],
+    surface_output_class: Union[Type[SurfaceOutput], Type[TimeAverageSurfaceOutput]],
 ):
     """Translate a single SurfaceOutput instance to solver config dict."""
     is_average = surface_output_class is TimeAverageSurfaceOutput
@@ -603,7 +603,7 @@ def _translate_single_surface_output(
 
 def translate_surface_output(
     output_params: list,
-    surface_output_class: Union[SurfaceOutput, TimeAverageSurfaceOutput],
+    surface_output_class: Union[Type[SurfaceOutput], Type[TimeAverageSurfaceOutput]],
     translated: dict,
 ):
     """Translate surface output settings.