Core/Instances: Fixed a bug that caused switching group leader inside active instance to cause players not being saved when a boss was killed.

Closes #5109
Core/Objects: Object scale will now also affect bounding radius and combat reach fields
Core/SAI: Add check so npc will not send text to pet. Also updated isPet() to IsPet().
Core/Gossip: Add log for GOSSIP_OPTION_TRAINER for missing conditions
Core: Some function renaming.
Core: More Function Renaming.
Core: More Function name updates
DB/Creature: Set Entry 18955 "Camera Shaker - 30-90 seconds" as trigger and remove random movement
DB/SAI: Fix SAI for Sunseeker Harvester