Body armour adjustments

[wgetJane]

• adds a new cvar for blocking crowbar damage
• removed crowbar damage being reduced by "classic" armour: crowbar damage was never blocked by armour in ttt
• set headshot damage to be reduced by default: this was never an oversight or mistake in ttt, it is a deliberate balance change, body armour initially only protected against shots to the torso but bku updated it to also protect against headshots and limbshots
• adds TTT2ArmorHandlePlayerTakeDamage hook (probably needs a better name)

this is a draft because this is untested right now, will test later

[wgetJane]

just tested and this seems to work fine, is the hook name "TTT2ArmorHandlePlayerTakeDamage" alright?

[TimGoll]

LGTM. I let this open so you can decide if you want to use migrations for this