Move handling of keywords to ParamTypeSubRenderer
Move handling of keywords to ParamTypeSubRenderer

because `typename` and `class` keywords can appear not only in
template parameters but in the types of function parameters as in

  template <typename T>
  void f(typename T::U);

RR2DO2/breathe,kirbyfan64/breathe,kirbyfan64/breathe,kirbyfan64/breathe,kirbyfan64/breathe,RR2DO2/breathe