Change organization of membership state views

src/sakia/data/processors/identities.py

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

src/sakia/gui/dialogs/connection_cfg/model.py

src/sakia/gui/dialogs/connection_cfg/view.py

src/sakia/gui/main_window/toolbar/controller.py

src/sakia/gui/main_window/toolbar/toolbar.ui

src/sakia/gui/navigation/informations/controller.py

src/sakia/gui/navigation/informations/informations.ui

src/sakia/gui/navigation/informations/model.py

src/sakia/gui/navigation/informations/view.py

tests/functional/test_connection_cfg_dialog.py