Peksa npc to Kotlin

What has been done in this MR?

• Port Peksa from Java to Kotlin
• Required for !1735 (merged)

What should testers check?

Go to barbarian village and interact with Peksa

• You can buy helms from Peksa
• You can sell helms to Peksa
• You can say no to talking to him
• You can right click and say trade

• I have tested these changes thoroughly.

• I used the relevant Thanos/Zaros tool for any JSON edits where possible, and have attached screenshots of any changes.