Core/Entities: First step to 128 bit guids

* Database fields storing full guid have been converted to BINARY(16)
Core/Misc: Optimized ByteBuffer::ReadString
Core/Entities: Second part of required database changes for migrating guids to 128 bit - all fields storing lowguid must be extended to uint64
Core/Entities: Added type definition to use for a low guids
Core/Entities: Third part of converting int to bigint guids in database
DB/Creatures: Updated `creature_template` to 6.0.2.19034
Core/Opcodes: Remove "direction" flag from some opcode ids

OpcodeTable will be split in two to support opcode direction
DB/SAI: Added SAI for first part of mobs before the gunship battle
I will add more when I will have more time.

(Picked from 3.3.5)
Fixed typo in ObjectGuid.h
Core/Corpses: Fixed loading corpse guid during server startup
Core: Fix build
Core/Entities: Fourth part of converting int to bigint guids in database
DB/Hotfixes: Added TaxiPathNode
DB/Hotfixes: Fixed some texts in broadcast_text that had double quotation marks
Core/Misc: First part of renaming to Blizzard's names
DB/Misc: Cherry Picking missing commits

Some fixes which I pushed to 3.3.5 which are also valid for 6.x.x but have been missed
Tools/Map extractor: Restored default configuration to make maps smaller at the cost of height data precision
Core/Guilds: Fifth part of converting int to bigint guids in database
Fixed SQL typo in characters_database.sql
Merge pull request #13462 from marc0303/6.x

Fixed SQL typo in characters_database.sql