Add Brazilian Portuguese translation #59

Proposal

Add Brazilian Portuguese (pt_BR) support to the advancedforms plugin.

Motivation

Our university is preparing to adopt the advancedforms plugin as part of its GLPI service management environment.

Brazilian Portuguese support is fundamental for our users and service desk team. Important form labels, reservation messages, validation errors, and workflow notifications should be available in Portuguese to ensure accessibility and effective adoption.

Without this translation, Portuguese-speaking users must interact with key parts of the plugin in English.

Scope

• Translate reservation, validation, table, notification, and pre-reservation messages.
• Include the compiled pt_BR.mo catalog alongside pt_BR.po.
• Ensure the translation works with GLPI 11.0.8 and 11.0.9.

A pull request with the implementation is available at #58.