Fix WW3 failing restart

[ezhilsabareesh8]

This PR fixes #97 by adding ice thickness (IC1) and floe diameter (IC5) to the restart write and read routines of WW3.

[anton-seaice]

If the configuration does not need ice thickness or floe diameter, will this change cause those restarts to fail? Or will this be compatible with all wave-ice propagation models in WW3

[micaeljtoliveira]

If the configuration does not need ice thickness or floe diameter, will this change cause those restarts to fail? Or will this be compatible with all wave-ice propagation models in WW3

That's a good question. I think it's better to check this before merging.

[ezhilsabareesh8]

If the configuration does not need ice thickness or floe diameter, will this change cause those restarts to fail?

I tested it with a different model which doesn't require these variables and it is working. I think it is because WW3 still write these variables in the restart files but it will be default values.