Scripts/Ulduar: Spellscripts for Mimiron

Cutting the commit in pieces, so that the diff can be viewed on github...
not the raid. the frostbomb spell targets fires, blizzard has some kind of safe zone where it will not be cast within because the frostbomb deals lethal damage and has a 30yd explosion range, in p2 the mid of the room is vital for surviving due to the laser barrage.