Add informations view

src/sakia/gui/component/controller.py

src/sakia/gui/homescreen/controller.py

src/sakia/gui/identities/controller.py

src/sakia/gui/identities/model.py

src/sakia/gui/informations/__init__.py

src/sakia/gui/informations/controller.py

src/sakia/gui/informations/informations.ui

src/sakia/gui/informations/model.py

src/sakia/gui/informations/view.py

src/sakia/gui/main_window/controller.py

src/sakia/gui/navigation/controller.py

src/sakia/gui/navigation/model.py

src/sakia/gui/network/controller.py

src/sakia/gui/status_bar/controller.py

src/sakia/gui/toolbar/controller.py

src/sakia/gui/txhistory/controller.py