[TF2] NPC damage notice fixes

[Megawolf7339]

Description

Adds a damage event to Halloween NPCs that didn't have them, meaning they give feedback with hitsounds/killsounds.

[Borloxos]

Do these changes also apply to the HHH, Merasmus, Monoculus, Skeleton King/Toastmaster, Scarecrows/Mobsters/Salmann (probably, as these are reskinned skeletons), and the RD robots? If not, could you add them to these entities as well?

[Megawolf7339]

they apply to all bosses, including custom ones, though krampus is implemented in a very strange way where his health never reaches 0, so the kill sound may not work

[Megawolf7339]

you were right i forgot those

[Borloxos]

Nice, thank you! I cannot test your branch right now, does this only add damage sounds and kill sounds or are damage numbers also included?

[gidi30]

Nice, thank you! I cannot test your branch right now, does this only add damage sounds and kill sounds or are damage numbers also included?

Damage sounds and damage numbers are handled by the same hud element so both will happen