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/TechDraw/Gui/ViewProviderViewPart.cpp

@@ -299,7 +299,7 @@ bool ViewProviderViewPart::setEdit(int ModNum)
                                         dvd->getNameInDocument());
     }
     else {
-        auto* view = dynamic_cast<TechDraw::DrawView*>(getObject());
+        auto* view = getObject<TechDraw::DrawView>();
         Gui::Control().showDialog(new TaskDlgProjGroup(view, false));
     }