Dynamically add node

src/sakia/app.py

src/sakia/data/processors/certifications.py

src/sakia/data/repositories/connections.py

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

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

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

src/sakia/gui/navigation/controller.py

src/sakia/gui/navigation/model.py

src/sakia/gui/navigation/view.py

src/sakia/models/generic_tree.py