Add support for Hibernate Validator `@CNPJ` annotation

[armandino]

Feature description

Checks that the annotated character sequence represents a Brazilian corporate tax payer registry number (Cadastro de Pessoa Jurídica).

• Supported data types: CharSequence
• Country: Brazil

Docs: https://docs.jboss.org/hibernate/stable/validator/reference/en-US/html_single/#_country_specific_constraints

@REGON implementation can be used for reference (RegonGeneratorSpec and RegonSpec).