BUNKER SILO UTILITIES

This script adds the following functions for bunker silos:
1. The silo can be closed again after it has been opened, so that it does not get wet when it rains. This can also be used to fix the bug that prevents the open silo from opening further.
2. If the silo has not finished fermenting, it can be opened again so that it can be filled further. In this way, the fermentation progress is lost.
3. The silo can be emptied completely.
4. The silo can be covered with different silo tarps.