Add CustomAction to TrafficCommand

This action is aligned with CustomCommandAction of OpenSCENARIO 1.0.

Signed-off-by: Pierre R. Mai <pmai@pmsf.de>

Author: tpajenkamp-dspace

osi_trafficcommand.proto

@@ -97,7 +97,11 @@ message TrafficAction
 
     // An EndActionsAction
     //
-    optional EndActionsAction end_actions_action = 7; 
+    optional EndActionsAction end_actions_action = 7;
+
+    // A CustomAction
+    //
+    optional CustomAction custom_action = 8;
 }
 
 //
@@ -505,3 +509,26 @@ message EndActionsAction
     //
     repeated Identifier target_action_id = 2; 
 }
+
+//
+// \brief Custom Action.
+//
+// This action assigns a custom command to a traffic participant.
+// The syntax and semantics of this action is implementation defined.
+// It is entirely up to each individual traffic participant which
+// custom commands it supports, if any, and how they must be phrased.
+//
+// \note This action is aligned with CustomCommandAction of OpenSCENARIO 1.0
+// providing a customizable user defined action.
+//
+
+message CustomAction
+{
+    // The Action Header
+    //
+    optional ActionHeader action_header = 1;
+
+    // The custom command given to the traffic participant.
+    //
+    optional string command = 2;
+}