💥 Units: switch to QE-native units for outputs

[mbercx]

Motivation in

https://qe-tools--161.org.readthedocs.build/en/161/units/

[codecov-commenter]

Codecov Report

❌ Patch coverage is 94.73684% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 88.47%. Comparing base (d0f8124) to head (b04e295).
⚠️ Report is 137 commits behind head on main.

Files with missing lines	Patch %	Lines
src/qe_tools/converters/aiida.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #161      +/-   ##
==========================================
- Coverage   89.77%   88.47%   -1.30%     
==========================================
  Files          11       23      +12     
  Lines         489     1102     +613     
==========================================
+ Hits          439      975     +536     
- Misses         50      127      +77     

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