/// @param[in] afb_req request : contains original request use to subscribe or unsubscribe
/// @param[in] subscribe boolean value, which chooses between a subscription operation or an unsubscription
/// @param[in] signals - struct containing vectors with signal_t and diagnostic_messages to subscribe
+/// @param[in] event_filter - stuct containing filter on the signal
///
/// @return Number of correctly subscribed signal
///