Add Exfil's API with a fallback to Source protocol

[altNightHawk]

Adds support for Exfil's new API, with automatic fallback to A2S query.

Features:

• Two-stage query strategy:
  • Stage 1 (Primary): HTTP API call to http://{host}:{port}/status
  • Stage 2 (Fallback): Source protocol (A2S query) via opengsq
• Comprehensive field mapping with multiple fallback options

Field Mapping:

API Format	Field	Output
Exfil	serverName	name
Exfil	players (int)	numplayers
Exfil	maxPlayers (int)	maxplayers
Exfil	playerList (array)	players
A2S	SteamServerName_s	name
A2S	Players_s (X/Y)	numplayers/maxplayers