[c2959] Add more content related to Thorim event

* Implement script for the Runic Colossus. This is required due to the Runic Smash spells
* Implement achievements 2971 and 2972
* Allow Thorim to constantly check for the players in the arena and trigger berserk if no player is found

(based on commit SD2-WotLK [2959] - 6b69286)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>