Implemented 3 Arena Quests Using New Event Quest Structure

[kbarkevich]

This Arena Quest PR uses the new quest encoding system.

Implemented 3 arena quests:

• Grudge Match: Royal Ludroth
• Grudge Match: Bird and Brute
• Grudge Match: Two Flames

Also updated city greeter text to reflect existence of arena quests.

[kbarkevich]

Rebased onto dev