Refactor BurerMonteiro into subfolder

[blegat]

The file started to be too big

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.36%. Comparing base (59d0138) to head (2cc5f6a).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #54   +/-   ##
=======================================
  Coverage   99.36%   99.36%           
=======================================
  Files          23       26    +3     
  Lines        1258     1259    +1     
=======================================
+ Hits         1250     1251    +1     
  Misses          8        8           

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