Gui: Use getObject<T>() helpers in classes

This commit is generated using regex based find and replace:

```
s/[\w:]+_cast\s*<([^>]+)\*>\s*\(\s*getObject\(\s*\)\)/getObject<$1>/
s/[\w:]+_cast\s*<([^>]+)\*>\s*\(\s*([^)]*)\s*->\s*getObject\(\s*\)\)/$2->getObject<$1>()/
```

To regenerate if needed.

src/Mod/Fem/Gui/TaskFemConstraintInitialTemperature.cpp

@@ -56,7 +56,7 @@ TaskFemConstraintInitialTemperature::TaskFemConstraintInitialTemperature(
 
     // Get the feature data
     Fem::ConstraintInitialTemperature* pcConstraint =
-        static_cast<Fem::ConstraintInitialTemperature*>(ConstraintView->getObject());
+        ConstraintView->getObject<Fem::ConstraintInitialTemperature>();
     std::vector<App::DocumentObject*> Objects = pcConstraint->References.getValues();
     std::vector<std::string> SubElements = pcConstraint->References.getSubValues();