Add stop functionality

micro_ros_agent/include/agent/Agent.hpp

@@ -38,6 +38,8 @@ public:
 
     void run();
 
+    void stop();
+
 private:
 
     eprosima::uxr::AgentInstance& xrce_dds_agent_instance_;

micro_ros_agent/src/agent/Agent.cpp

@@ -176,6 +176,11 @@ void Agent::run()
     return xrce_dds_agent_instance_.run();
 }
 
+void Agent::stop()
+{
+    return xrce_dds_agent_instance_.stop();
+}
+
 std::shared_ptr<graph_manager::GraphManager> Agent::find_or_create_graph_manager(eprosima::fastdds::dds::DomainId_t domain_id)
 {