Scripts/Ulduar: Implement Mimiron

TODO:
Make ACU hover properly (not fly, but hover).
Fix laser barrage visual not always being infront of VX-001. Problem is
caused by bad orientation update on spellcast.
Scripts/MagistersTerrace: fix possible crash
Core/Misc: Fix gcc warnings
Core/Battleground: refactored BattlegroundScore
(original code by Machiavelli)
Scripts/Commands: fixed possible client crash with .go command
DB/SAI: Fix more runtime errors 

By dr-j
Core/Battleground: removed hardcoded levels of alterac valley npcs
DB/Misc: Missing Graveyard in Zone 44

Closes #9724
DB/Misc: Karen No (and related quests)

By Wylath, closes #9217
DB/Conditions: Arcanum of the stalwart protector

Closes #10163
Merge pull request #12268 from Unholychick/patch_mimironnew

Scripts/Ulduar: Implement Mimiron
Revert "Scripts/Ulduar: Implement Mimiron"
Merge pull request #12382 from TrinityCore/revert-12268-patch_mimironnew

Revert "Scripts/Ulduar: Implement Mimiron"
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore into ghbb

Conflicts:
	src/server/game/Battlegrounds/Battleground.cpp
	src/server/game/Battlegrounds/Battleground.h
	src/server/game/Battlegrounds/BattlegroundMgr.cpp
	src/server/game/Battlegrounds/Zones/BattlegroundAV.cpp
	src/server/game/Globals/ObjectMgr.h
Revert "Core/Battleground: removed hardcoded levels of alterac valley npcs"

This reverts commit 745833ccbc09660209ec2c48db3d020c07ff22c2.

Conflicts:
	src/server/game/Battlegrounds/Zones/BattlegroundAV.cpp
Revert "Core/Battleground: refactored BattlegroundScore"

This reverts commit c28345e279f31af2fa32df2411325ccfabe06fc8.

Conflicts:
	src/server/game/Battlegrounds/Battleground.cpp
	src/server/game/Battlegrounds/Battleground.h