FR403 Panzerfaust

This is the transition model between [FR402](https://robocraftgarage.shaf.fun/robots/78) and [FR404](https://robocraftgarage.shaf.fun/robots/80). It is lower than [FR402](https://robocraftgarage.shaf.fun/robots/78) to get better survivability. Its pivot steering is rigid, even unable. This problem followed [FR402](https://robocraftgarage.shaf.fun/robots/78).