Avoid side effects in setup_storage

[bouthilx]

Why:

The function was modifying the configuration dictionary, causing
side-effects if the user intended to reuse the configuration dictionary
later on.

[bouthilx]

orion.storage.base#setup_storage() modifie ses paramètres

[codecov-commenter]

Codecov Report

Merging #444 into develop will decrease coverage by 0.00%.
The diff coverage is 33.33%.

@@             Coverage Diff             @@
##           develop     #444      +/-   ##
===========================================
- Coverage    48.96%   48.96%   -0.01%     
===========================================
  Files           79       79              
  Lines        13644    13647       +3     
  Branches       328      328              
===========================================
+ Hits          6681     6682       +1     
- Misses        6947     6949       +2     
  Partials        16       16              

Impacted Files	Coverage Δ
tests/unittests/storage/test_storage.py	16.18% <33.33%> (+0.12%)	⬆️

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