Fix Nubmage gossip routing and Daish formation

[RovxBot]

This pull request introduces several improvements and fixes across database formation logic, NPC gossip handling, and repository ownership assignment. The most significant changes involve correcting formation member registration and angle conventions, improving robustness in NPC gossip option resolution, and updating code ownership.

Formation and database logic improvements:

• Updated the creature_formations entry for Daish: Only the escorts are now registered as members of the leader's formation, and follow angles are stored in degrees (90.0 for left flank, 270.0 for right flank), aligning with AzerothCore conventions. Also, removed the leader's entry as a member and changed groupAI to 0 for the escorts.

NPC gossip handling robustness:

• Enhanced the npc_nubmage gossip handler to resolve the selected action via PlayerTalkClass before processing. This prevents misrouting when menu rows shift or become stale, ensuring the correct portal destination is selected regardless of how the gossip option arrives.

Repository ownership:

• Added a new code owner (@rovxbot) for all files in .github/CODEOWNERS, improving repository maintenance and accountability.