Added script for creature 6066 (Earthgrab Totem)

Workaround because creature 6066 (Earthgrab Totem) is summoned by spell
8376 which has wrong spell effect 42 (SPELL_EFFECT_SUMMON_GUARDIAN)
instead of spell effect 87 (SPELL_EFFECT_SUMMON_TOTEM_SLOT1) preventing
the summoned creature to properly use the TotemAI. Hence, we have to
emulate the right AI with ACID (eventAI)