traditional Chinese localization, string extraction, icon clone and resize

1. add zh-tw for traditional Chinese Language
2. extract some hard-code string to resource file
3. clone rssi-icon to radio-icon and resize radio-icon to the same size with other menu-icon
one of. Another reason is that there are two following Toast message coming. One is "No drone location available" and the other is "Long press to activate drone auto panning". I think while drone is not connecting, the "long press" message is not necessary to show.