add icon tools
The icon tools include to polish ICON model output (currently that is, attaching various coordinate fields to the output dataset).
Currently, the vertical levels
- for atmosphere are "generalized height levels", thus just a list of numbers according to the size of the level dimensions
- for ocean are read from the ocean namelist (and only added to the output if the namelist is supplied)
- for land output are hard-coded (because I didn't yet find a good way to get them dynamically)
Edited by Tobias Koelling