feat: possibility to persist NPC on map with /n talkaction

[lamonato29]

Description

Sometimes, we need to add a NPC to the map, and we can do this in two ways:
We can add it via RME or we can add it in the XML directly.

This PR will give the possibility to persist the recently spawned NPC on the map, just using a command with GOD character.
It will be placed in GOD's position.

USAGE:
Add the param true after the NPC Name.

/n NpcName,true

This will add the NPC tag to the npcs xml file.

Behaviour

Actual

Use /n npcName, the NPC will be spawned and removed after the server closes.

Expected

Use /n npcName when you want to add a temporary NPC to the map.
Use /n npcName,true when you want to add a persistent NPC to the map.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested

Join the game with GOD, spawn a npc with the following command:
/n npcName,true

Close and reopen the server. The NPC will spawn in the same position.