DDS Gateway Housekeeping

[mossmaurice]

Brief feature description

The following maintenance tasks need to be done to keep the dds gateway code healthy:

• Update CMake build to retrieve cyclonedds-cxx library from the official github repository
• Refactor gateways to use new publisher/subscriber APIs
• Bring test coverage up to at least 70%
• Utilize the improved waitset to make the gateways reactive
• make DataWriter::write return a cxx::expected
• add convertor from mepoo::ChunkHeader to dds::IoxChunkDatagramHeader
• Findings budrus test run:
• No documentation how to setup a config file
• When building with the build script the cyclone libraries are in ...build/dependencies/install/lib64 (not documented but needed for setting LD_LIBRARY_PATH
• The default config should include the icedelivery topic. This allows to have a first running example with icedelivery
• "Terminated" endless loop when RouDi gets killed?
• Replace Channel concept with cxx::pair (needs to be implemented)

These should be completed before further extension of the gateway.

Some ToDo items from #360:

• Modify implementation of iox::dds::CycloneDataReader::hasNewSamples() so it can be made const
• Resolve mismatch of uint sizes of nextSampleSize in CycloneDataReader::peekNextSize()
• Add error handling to semaphore creation in Iceoryx2DDS main.cpp
• Simplify three nested lambdas in void DDS2IceoryxGateway<channel_t, gateway_t>::forward(). For example

  auto maybeNextSize = reader->peakNextSize();
  if(!maybeNextSize)
  {
      continue;
  }
  auto& size = maybeNextSize.value();
  ...
  

  and only use for for reader->takeNext the approach with the lambda.
  It would be more code, but also less complex