DB/SAI/Waypoints: Fix some sai and add some missing waypoints.
Core/Scripting: Properly name boss_thorngrin_the_tender file.
Core/Scripting: Rename zone scripts.
Core/Scripting: Some file name updates.
DB/Scriptremoval: Remove not working scripts from gameobject_scripts: the objecttype is not correct for this useage
Core/Misc: Missing changes from 8968dbc (Partial revert of 2292025)
Closes #8843
DB/Script: Add the Undead Postman script to the proper mailboxes and use SAI instead of gameobject_script

TODO: add Parcel Packet when i have more information about it
Core: Fix warning
Merge branch 'master' of github.com:TrinityCore/TrinityCore into mmaps