[ui] refactor ui

bitmask.pro

docs/hacking-qml.rst

gui/backend.go

gui/components/BoldLabel.qml

gui/components/Footer.qml

gui/components/Header.qml

gui/components/Help.qml

gui/components/Home.qml

gui/components/Icon.qml

gui/components/LightLabel.qml

gui/components/Locations.qml

gui/components/MainView.qml

gui/components/MaterialButton.qml

gui/components/Preferences.qml

gui/components/Spinner.qml

gui/components/Splash.qml

gui/components/StatusBox.qml

gui/components/Style.qml

gui/components/Systray.qml

gui/components/VPNButtonBase.qml