fix: resolve build errors — ToolBarItem incomplete type and ReportException method name

- Workbench.h: replace forward declaration of ToolBarItem with #include <Gui/ToolBarManager.h>
  so that ToolBarItem::DefaultVisibility can be used as a default parameter (line 283)
- ApplicationPy.cpp: fix ReportException() → reportException() to match
  the method name declared in Base::Interpreter.h

src/Gui/ApplicationPy.cpp

@@ -2271,7 +2271,7 @@ PyObject* ApplicationPy::sRegisterEditingContext(PyObject* /*self*/, PyObject* a
         }
         catch (Py::Exception&) {
             Base::PyException e;
-            e.ReportException();
+            e.reportException();
             return false;
         }
     };
@@ -2322,7 +2322,7 @@ PyObject* ApplicationPy::sRegisterEditingOverlay(PyObject* /*self*/, PyObject* a
         }
         catch (Py::Exception&) {
             Base::PyException e;
-            e.ReportException();
+            e.reportException();
             return false;
         }
     };