Fix ShouldDamage, MobjDamage and MobjDeath hooks all messing up the pushing of variables to Lua as function args, by adding damagetype support where it was missing!

The above issue occured only if you had both a generic hook and a type specific hook for a particular hook type. This way, the stack is never updated to include damagetype at the start, and all pushes of the variables get offsetted by 1 compared to what they should be, once the code *expects* damagetype to be included in it.