The REGISTER_INSTANCE and LOOKUP_INSTANCE DDS Writer Operations return
an Instance Handle. Until now this instance Handle was returned via the
Data output interface of the dds_writer (ready_out, valid_out,
data_out_last_word_out).
This was changed, so that the dds_writer directly outputs the Instance
Handle via a dedicated port while asserting the done Signal.
This has the result that the <TYPENAME>_writer_wrapper no longer
"exports" data out signals from the dds_writer.
All relevant instantiations and testcases are changed accordingly
