Added ICON fixes for hfls and hfss

[diegokam]

Description

This pull request adds support for variables hfls and hfss for ICON.
For these variables it is necessary to change the sign of the input data.

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Checklist

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.12%. Comparing base (5941300) to head (f938a53).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2360   +/-   ##
=======================================
  Coverage   94.12%   94.12%           
=======================================
  Files         241      241           
  Lines       13387    13393    +6     
=======================================
+ Hits        12600    12606    +6     
  Misses        787      787           

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[schlunma]

Thanks @diegokam, looks good to me! 🚀

Do you want to add yourself to the list of contributors here and here?

[diegokam]

Thanks @diegokam, looks good to me! 🚀

Do you want to add yourself to the list of contributors here and here?

Sure, I am going to add it! Thanks!

[schlunma]

Awesome! I successfully tested this with real data.

Merging this now since we need it for a demonstration next week and this only affects ICON data.