Fixed signal items, Fixed mission availability, Changed goods availability

Mantises are very vulnerable to burn wounds. Mantises drop swim bladders, weapons are cheaper at settlements, completely reworked Endworm to be a challenging, insanely hard enemy. It no longer ignores divers. Explosvie rounds - removed stun parameter and added burn damage+radius increase. Piercing ammo - Added laceration wounds and made mudraptor shells more vulnerable to lacerations. Increased Flamer damage.