efl sel manager - flush wl conenction in cnp to avoid hangs...

we don't force buffers to flush in wl... this will fix that and force
them removing an ugly hang for possibly seconds in cnp from client to
client or even within a client.

remember:

flush your mush.

@fix

src/lib/elementary/efl_ui_selection_manager.c

@@ -2723,6 +2723,7 @@ _wl_selection_send(void *data, int type EINA_UNUSED, void *event)
    free(data_ret);
 
    close(ev->fd);
+   ecore_wl2_display_flush(ev->display);
    return ECORE_CALLBACK_PASS_ON;
 }
 
@@ -2763,6 +2764,7 @@ _wl_dnd_end(void *data, int type EINA_UNUSED, void *event)
 
    seat_sel->accept = EINA_FALSE;
 
+   ecore_wl2_display_flush(ev->display);
    return ECORE_CALLBACK_PASS_ON;
 }
 
@@ -2976,6 +2978,7 @@ _wl_efl_sel_manager_selection_get(const Efl_Object *request, Efl_Ui_Selection_Ma
                                                      _wl_selection_receive, sel);
 
             ecore_wl2_offer_receive(offer, (char*)sm_wl_convertion[i].translates[j]);
+            ecore_wl2_display_flush(ecore_wl2_input_display_get(input));
             return EINA_TRUE;
          }
      }