Scripts/Auchindoun: Update Talon King Ikiss' script to EventMaps

Codestyle

Missing include
Scripts/UtgardeKeep: Update Skarvald & Dalronn scripts to EventMaps

* Simplified creature_texts enum that was sort of confusing
* Removed hack to spawn ghosts using the proper spells
Merge pull request #12978 from Nyeriah/patch-auchi

Scripts/Auchindoun: Update Talon King Ikiss' script to EventMaps
Merge pull request #12992 from Nyeriah/patch-uk

Scripts/UtgardeKeep: Update Skarvald & Dalronn scripts to EventMaps
Core/Misc: Refactor scripts to fix static analysis warnings

First batch of fixes targeting 100 issues reported by Coverity