`br-utils` v3

[juliolmuller]

Version 3+ will be structured similarly yo the PHP and Python version of the packages:

• Main component should be object-oriented, so a class should wrap wrapping the use of formatting, generating and validating CNPJ and CPF.
• Re-export resources from packages cnpj-utils and cpf-utils.
• An instance of BrUtils should be provided with the default option.
• Update unit tests
• Update documentation