DB/Creature: Add missing spawns for Amphitheater of Anguish
Core/Auras: Fixed a crash happening when different vehicle auras from the same caster stacked on one target

Closes #10050
DB/Misc: Cleaning db
Core/Scripting: Add spell script for spell 55945 Spectator - Cheer Trigger
DB/creature_text: Add missing text for Amphitheater Vendor
Core/Scripting: Add spell script for vendor bark trigger
DB/waypoints: Add waypoints for two Amphitheater Vendors
DB/Misc: restore lost data