Improvement in internal frame generator

Improve way how internal packet generator is executed (mostly in HLS simulation), allowing to make it more similar to "standard" network collection. This required to modify network stack cores, so they can be executed in parallel in HLS simulation.

acquisition_device/HLSSimulatedDevice.cpp

@@ -164,8 +164,6 @@ void HLSSimulatedDevice::FPGA_StartAction(const DiffractionExperiment &experimen
         if (ret)
             throw JFJochException(JFJochExceptionCategory::AcquisitionDeviceError,
                                   "Error running internal packet generator");
-    } else {
-        data_source = STREAM_MERGE_SRC_100G;
     }
     action_thread = std::thread(&HLSSimulatedDevice::HLSMainThread, this );
 }