DB/SAI: Fix "Badlands Enraged Rock Elemental" event spam
Closes #11802
DB/Creature: Remove 2 no longer existing mobs

Gal'darah Image and Ingvar the Plunderer Image where removed with the introduction of 3.3 weekly quests.
Scripts/Misc: Small code optimizations
Core/Commands: Handle "" as empty string argument

Fixes #11548
Core/Misc: Fix warning
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore into ghbb

Conflicts:
	src/server/scripts/Northrend/UtgardeKeep/UtgardePinnacle/boss_skadi.cpp