Log timestamp arrived to debug observer

source/RobotAPI/libraries/armem_robot_state/server/proprioception/RobotUnitReader.cpp

@@ -146,6 +146,9 @@ namespace armarx::armem::server::robot_state::proprioception
                 debugObserver->setDebugObserverDatafield(
                     "RobotUnitReader | RT Timestamp Since Last Iteration",
                     data.back().timesSinceLastIterationUSec);
+                debugObserver->setDebugObserverDatafield(
+                    "RobotUnitReader | Timestamp Arrived in RSM",
+                    armarx::DateTime::Now().toMicroSecondsSinceEpoch());
             }
         }
         if (data.empty())