Refatoracao do codigo dos utilitarios de cpf

[camilamaia]

• Remoção de lógica repetida
• Reorganização da ordem das funções no arquivo cpf.py e test_cpf.py

Closes #104

[codecov]

Codecov Report

Merging #105 (5ce3307) into main (e2e0028) will increase coverage by 0.81%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #105      +/-   ##
==========================================
+ Coverage   97.64%   98.46%   +0.81%     
==========================================
  Files           3        3              
  Lines          85       65      -20     
==========================================
- Hits           83       64      -19     
+ Misses          2        1       -1     

Impacted Files	Coverage Δ
brutils/cpf.py	100.00% <100.00%> (+2.04%)	⬆️

[antoniamaia]

@camilamaia 👍🏼