Add WoT component, remove Explorer from sources

src/sakia/data/graphs/__init__.py

src/sakia/data/graphs/base_graph.py

src/sakia/data/graphs/explorer_graph.py

src/sakia/data/graphs/wot_graph.py

src/sakia/data/processors/certifications.py

src/sakia/gui/navigation/controller.py

src/sakia/gui/navigation/graphs/base/controller.py

src/sakia/gui/navigation/graphs/base/graph_tab.py

src/sakia/gui/navigation/graphs/base/model.py

src/sakia/gui/navigation/graphs/explorer/__init__.py

src/sakia/gui/navigation/graphs/explorer/controller.py

src/sakia/gui/navigation/graphs/explorer/edge.py

src/sakia/gui/navigation/graphs/explorer/explorer.ui

src/sakia/gui/navigation/graphs/explorer/graphics_view.py

src/sakia/gui/navigation/graphs/explorer/model.py

src/sakia/gui/navigation/graphs/explorer/node.py

src/sakia/gui/navigation/graphs/explorer/scene.py

src/sakia/gui/navigation/graphs/explorer/view.py

src/sakia/gui/navigation/graphs/wot/controller.py

src/sakia/gui/navigation/graphs/wot/model.py