Expand ICON-XPP fix for new model version

[schlunma]

Description

I found two changes in ICON-XPP output that require changes in our on-the-fly CMORization:

• Sea ice data has depth variable ice_class instead of lev
• The depth and depth_2 coordinates have been switched (one is cell centers, one cell boundaries)

All changes here are fully backwards-compatible.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.70%. Comparing base (6a382f6) to head (347d973).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3014   +/-   ##
=======================================
  Coverage   95.69%   95.70%           
=======================================
  Files         267      267           
  Lines       15758    15768   +10     
=======================================
+ Hits        15080    15090   +10     
  Misses        678      678           

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[axel-lauer]

I tested this with ocean and sea ice data. Works nicely! Thanks @schlunma!