DB/SAI: add SAI for Wretched Skulker/Bruiser/Husk

Closes #10034
DB/Loot: Gnomish Grenades have Very High drop chance

Closes #10086
DB/Player: add Wooly Mammoth & Armored Brown Bear to factionchange

Closes #10098
Core/Scripting: Gyth event still not finished but completable.
DB/Creature: Fix startup error
DB/Misc: Remove some db strings and waypoint scripts. Repalce with creature text and SAI.
DB/Misc: move text from db string to creature_text.
Db/Misc: More db strings to creature text
DB/Misc: More convertions from db string. SAI waypoints not working correctly, core issue. Action 66 turn to not working, core issue.
DB/waypoints: Add some missing waypoints
DB/Misc: Missing spawn and pathing for UBRS
DB/Misc: Typo fix
Core/Scripting: More updates for BRS instance. Added missing scripts for urok and gizrul.
DB/Misc: Fix some startup errors.
DB/Creature: Fix some bad spawning in LBRS
DB?Creature_template: Fix a few creatures with AIName and Scriptname.
Scripted/Naxxramas: Fix Four Horsemen Chest
Scripted/Naxxramas: Missing cleanup in f90078f979eacbaa50c14418f82d9c58a4c84b33 :P
Core/Scripting: Move most if Illidan script text to creature text.
Core/Scripting: Update spirit of Olum to use db gossip.