Translate demographics survey elements into Spanish

[mario-bermonti]

Description

Translates all the elements from the research_package surveys into Spanish. It also setups the basics for the general internationalization for the app.

A pull request will be submitted to the research_package when the team has provided feedback.

Related Issue

Type of Change

• 📚 Examples / docs / tutorials / dependencies update
• 🐞 Bug fix (non-breaking change that fixes an issue)
• 🔧 Maintenance (non-breaking change that improves code)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix
• 🔐 Improvements to the CI workflow

Checklist

• I've read the project's code of conduct.
• I've read the contributing guide.
• I've written tests for all new methods and classes that I created.