Convert Mount Vendor script to DB 

Move CPP script npc_mount_vendor to db 
* Sniffed gossip menu for Veron Amberstill as we did not have this
* There is more than one text per gossip for these, readded all gossip menus we have to include the ones that where not in db already
* Conditions for vendor option and texts to only sell to elegible to players and show correct texts

We do not have text for Dreanei or dwarf have not checked gnome one since that one had already been moved to db since npc had sai

closes #13088
Scripts/Misc: some small changes after recent commits
DB/Misc: Some additions to https://github.com/TrinityCore/TrinityCore/commit/137c8a7de9beaa90441c5aa38e14ad0b09bebffe

Some additions to https://github.com/TrinityCore/TrinityCore/commit/137c8a7de9beaa90441c5aa38e14ad0b09bebffe

* Add a missing npc_text where gossip menu had already existed in db with this text and core script sent this text as gossip but text was not in db
* Correct option id for a option.
SQL: Fix typo.

Fix typo in 587d87d2ccc888b0a881be4bfaab150422edaec8.
Remove a Gossip Script which is already in DB

Remove script for Khadgar all of the gossip menus and options are already in db and this is only a gossip script, will deal with db stuff in next commit
a correction
Core: Fix typo in cec2cc806b418997f387bf1324454b7b76b9f0fa
Core/Misc: Get rid of some warnings.
Core/Misc: Kill few more warnings.
DB/Misc: Random fixes/error fixes
Core/Group: Update enum GroupType