Add regions to dataset

[paulofreitas]

The project is mature enough to go further and include regions in dataset files.
This will require, at least but not limited to:

• geodatabr.dataset.schema
  • New Region entity class
  • New region relationship in other entity classes
  • Inclusion of Region entity class in Entities collection
• geodatabr.dataset.repositories
  • New RegionRepository class
• geodatabr.dataset.seeders
  • New RegionSeeder class
• geodatabr.dataset.services
  • New SIDRA_REGION constant in geodatabr.dataset.services module
• Changes to localization files