Split Mob::SetAttackTimer into Client and NPC methods

This was the easiest way to NPCs delay settings to be sane in the database.
The functions are cleaner since there is no specific logic to change
behavior depending on if they're a client or not.
Change NPCs to have their attack delay set in DB

This gives us a much more straight forward way of setting mob
attack delay with respect to live.

The attack_delay column is in 10ths of seconds, just like weapons are
The attack_speed is left for references for now.
Change scale of GetPermaHaste()