New documents services

src/sakia/core/account.py

src/sakia/data/connectors/bma.py

src/sakia/data/entities/identity.py

src/sakia/data/processors/identities.py

src/sakia/gui/dialogs/community_cfg/controller.py

src/sakia/gui/password_asker.py

src/sakia/services/__init__.py

src/sakia/services/documents.py

src/sakia/tests/technical/test_documents_service.py