eCAL::hdf5: enhance API to save information with unique ID.

[KerstinKeller]

We want to introduce a new eCAL HDF5 File version v6.

Current file layout:

meas.hdf5
 - 0 (binary payload)
 - 1 (binary payload)
 - 2 (binary payload)
 - person (table)
    - attribute topic type
    - attribute topic descriptor

To facilitate saving TopicDescriptionInformation with different descriptors, we need to change the structure quite a bit

 - 0 (binary payload)
 - 1 (binary payload)
 - 2 (binary payload)
 - person
    - PubID
      - TypeInformation
        - name
        - schema
        - descriptor
      - content

Questions

• What datatype should we use? (std::uint64_t?)
• How do we make the signature (std::string, std::uint64t) or put them in a struct?

Todo:

• Change API
• Create ecal_meas_file_v6.h/cpp for new reader implementation and ecal_meas_file_writer_v6.h/cpp for new writer implementation
• Update documentation