CustomIO for CounterStrikeSharp

Fixes missing keyvalues from CSS/CS:GO. Idea taken from cs2fixes

Features:

1. Adds a custom Input-Output as in CSS/CS:GO: From cs2fixes

Installation:

1. Compile or copy CS2-CustomIO to counterstrikesharp/plugins/CS2-CustomIO folger
2. Copy CS2-EntityFix.json to counterstrikesharp/gamedata folger
3. Restart server