Updating pt-BR translations (fixing some existing entries, adding missing ones and removing unused ones as well)

[cassiano]

This PR synchronizes the pt-BR translation file with the en-US one, by adding missing entries. It also fixes some incorrect translations and updates others with better texts.

Changes:

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named

[cassiano]

I still see the Test and lint code base Expected — Waiting for status to be reported warning above. I have run the linter and tests locally and everything seems fine. What else needs to be done from my side, please?