implement H5PartConverter and modify various things

Add 
 - H5Part converter with HDF lib
 - staging tool
 - some utility functions and its unit test
 - user manual
 - cmake macros to find dependent libs

Bug fix:
 - PDMlib::Impl::Migrate
 - MakeTimeStepList

Modified:
 - CmakeLists.txt (use find_package)
 - migration test (use both NIJK and IKN vector container)