SDK: Implement WaitForExecutingAgents

* Require DDS 2.5.22
* Apply in meaningful places
* Adapt test fixture

test/sdk/TopologyFixture.h

@@ -61,10 +61,7 @@ struct TopologyFixture : ::testing::Test
         LOG(info) << mDDSTopo;
         auto n(mDDSTopo.GetNumRequiredAgents());
         mDDSSession.SubmitAgents(n);
-        mDDSSession.WaitForIdleAgents(n);
         mDDSSession.ActivateTopology(mDDSTopoFile);
-        std::this_thread::sleep_for(std::chrono::seconds(1)); // TODO implement WaitForActiveAgents
-        mDDSSession.RequestAgentInfo();
     }
 
     auto TearDown() -> void override {