Rename a method to reflect its purpose

Co-authored-by: Pedro Gomes <38071223+pcarruscag@users.noreply.github.com>

Author: TobiKattmann

SU2_CFD/include/variables/CVariable.hpp

@@ -416,7 +416,7 @@ class CVariable {
   /*!
    * \brief Store the adjoint solution of the extra adjoint into the external container.
    */
-  void Add_SolutionExtra_To_ExternalExtra() {
+  void Set_ExternalExtra_To_SolutionExtra() {
     assert(SolutionExtra.size() == ExternalExtra.size());
     for (auto iEntry = 0ul; iEntry < SolutionExtra.size(); iEntry++)
       ExternalExtra[iEntry] = SolutionExtra[iEntry];

SU2_CFD/src/solvers/CSolver.cpp

@@ -2207,7 +2207,7 @@ void CSolver::Add_Solution_To_External() {
     base_nodes->Add_External(iPoint, base_nodes->GetSolution(iPoint));
   }
 
-  base_nodes->Add_SolutionExtra_To_ExternalExtra();
+  base_nodes->Set_ExternalExtra_To_SolutionExtra();
 }
 
 void CSolver::Update_Cross_Term(CConfig *config, su2passivematrix &cross_term) {