[12552] Unify text-display functions

Remove MonsterText, MonsterYell, MonsterEmote, MonsterWhisper functions (int32 entry versions) and replace with a generic MonsterText function

Partly implement cmangos/mangos-wotlk#123
[12553] Fix some target-type handling for EventAI

Also increase log-output for bad target-types
[12554] EventAI - Add more developing error output