Adding pt_BR CNPJ alphanumeric generator to Company provider

[rpmoura]

What is the reason for this PR?

• A new feature
• Fixed an issue (resolve #ID)

Author's checklist

• Follow the Contribution Guide
• New features and changes are documented

Summary of changes

Review checklist

• All checks have passed
• Changes are added to the CHANGELOG.md
• Changes are approved by maintainer

[arthurtavaresdev]

Hey @bram-pkg and fellow maintainers,

This is a very important change for the entire Brazilian community. Starting in July 2026, the Brazilian government will require all company Tax IDs (CNPJ) to support alphanumeric characters instead of being limited to numeric values only.

This functionality is widely used in testing, data generation, and validation scenarios, making support for this change particularly important for Brazilian developers and organizations.

Given the upcoming regulatory requirement, it would be greatly appreciated if this proposal could be reviewed and considered for merge as soon as possible.

Thank you all for your time and consideration.