CppEditor: Add enclosing template on "Add Definition"

The template id for the class name is missing, but it's better than
nothing.

For example:

template<class T>
class Foo
{
  void func(); // Add Definition
};

// The following lines are added
template<class T>
void Foo::func() // Should be Foo<T>::func
{
}

Change-Id: I60a0cbd348985def3dfb7037067786e942278593
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/cppeditor/cppquickfixes.cpp

@@ -2567,6 +2567,7 @@ public:
         oo.showFunctionSignatures = true;
         oo.showReturnTypes = true;
         oo.showArgumentNames = true;
+        oo.showEnclosingTemplate = true;
 
         if (m_defpos == DefPosInsideClass) {
             const int targetPos = targetFile->position(m_loc.line(), m_loc.column());