Add light mode for hdf5 data export #6
Description
The current simulation.hdf5 is very sparse and takes a lot of space in the buffer.
To run farms simulation with an optimization algorithm. (e.g. NSGA-II)
Multiple instances of simulation run at the same time and the output file should be clean and only save data of interest to reduce storage usage.
This was previously fixed in ponyo distribution of farms_sim and reviewd by @jarreguit . If the previous PR was still viable, I can implement it again in farms v0.2