tdf#115600 Turn design mode on to Navigate by Control

Navigate by Control only works in design mode so turn design mode on
when Navigate by Previous or Next Control button is pressed.

Change-Id: I26a565758672c8dd1ec8bf979b199e8b240424e3
Reviewed-on: https://gerrit.libreoffice.org/70644
Tested-by: Jenkins
Reviewed-by: Jim Raykowski <raykowj@gmail.com>

sw/source/uibase/uiview/viewmdi.cxx

@@ -401,8 +401,11 @@ IMPL_LINK( SwView, MoveNavigationHdl, void*, p, void )
             }
         }
         break;
-        case NID_DRW :
         case NID_CTRL:
+            if (!rSh.GetView().IsDesignMode())
+                rSh.GetView().GetFormShell()->SetDesignMode(true);
+            [[fallthrough]];
+        case NID_DRW:
         {
             bool bSuccess = rSh.GotoObj(bNext,
                     m_nMoveType == NID_DRW ?