Fixed/updated pt-BR strings

[thiagojramos]

Due to the poor pt-BR translation, I redid all the strings from scratch based on the English file and updated the missing ones.

Note: I'm aware that there's also the option to translate via poeditor, and I even made some changes there a few days ago. However, I'm not a big fan of platforms like poeditor, Crowdin, etc.

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[thiagojramos]

I have read the CLA Document and I hereby sign the CLA

[mohnjiles]

Thank you!