feat: add translation to Brazilian Portuguese

[misteregis]

PRs relating to the v4 will be closed and locked.

• Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...). If this is a fix, please tag a bug.

0 Feature - Added Portuguese (Brazil) localization support

• What is the current behavior? (You can also link to an open issue here)

0 Currently, there is no Portuguese (Brazil) localization available for Tempus Dominus. Users who need pt-BR locale support have to either use a different locale or create their own custom localization.

• What is the new behavior (if this is a feature change)?

This PR adds complete Portuguese (Brazil) localization support including:

• All UI text translations for date/time picker interface
• Proper date and time formatting according to Brazilian standards (dd/MM/yyyy, H:mm)
• Ordinal number formatting with "º" suffix
• Week starts on Monday (startOfTheWeek: 1)
• 24-hour time format (hourCycle: 'h23')
• Comprehensive translations for all picker actions and navigation elements

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

No breaking changes. This is a purely additive feature that adds a new locale option without affecting existing functionality.

• Other information:

• The localization follows the same structure and patterns as existing locale files
• All translations are culturally appropriate for Brazilian Portuguese speakers
• Date formats follow Brazilian conventions (dd/MM/yyyy)
• Time formats use 24-hour notation which is standard in Brazil
• This enhancement improves accessibility for Portuguese-speaking users in Brazil

[lucaslm]

Just a note for any reviewer. I've notice this merge request adds the exact same locale file as the request I've opened, which is #2966. I do not care which one gets merged, as long as one of then does.