[ui] refactor ui

gui/resources/gear-fill.svg

gui/resources/globe.svg

gui/resources/help.svg

gui/resources/icon-noshield.svg

gui/resources/location.svg

gui/resources/power.svg

gui/resources/quit.svg

gui/resources/reception-0.svg

gui/resources/reception-2.svg

gui/resources/reception-4.svg

gui/resources/riseup-icon.svg

gui/resources/riseup-logo.png

gui/resources/settings.svg

gui/resources/speed-green.svg

gui/resources/speed-red.svg

gui/resources/speed-yellow.svg

gui/resources/spy.gif

gui/resources/tools.svg

gui/themes/themes.js

pkg/backend/init.go