New search_user component

res/ui/certification.ui

res/ui/transfer.ui

src/sakia/core/app.py

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

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

src/sakia/gui/graphs/wot/wot_tab.ui

src/sakia/gui/network/model.py

src/sakia/gui/network/table_model.py

src/sakia/gui/search_user/__init__.py

src/sakia/gui/search_user/controller.py

src/sakia/gui/search_user/model.py

src/sakia/gui/search_user/search_user.ui

src/sakia/gui/search_user/view.py

src/sakia/gui/toolbar/controller.py

src/sakia/gui/txhistory/model.py

src/sakia/gui/txhistory/view.py

src/sakia/gui/widgets/search_user.py