Add Gunship Mercenary Camp to Dalaran

[tdauth]

• https://www.hiveworkshop.com/threads/gilneasgunship.140576/
• https://www.hiveworkshop.com/threads/arcanegunship.270286/
• https://www.hiveworkshop.com/threads/skyfire-gunship.272359/

[tdauth]

Gunships have turrets.