Assigning zones to pawns on another faction's tile is broken

[mibac138]

You can trigger this bug by:

1. starting a multifaction server
2. have 2 people on the server, each with their own faction
3. one person must have a pawn on the other player's map, then create a zone and restrict a pawn to that zone. When pathing updates, this should trigger the problem.

This issue is caused by the PathFinder having faction-related data, such as areas, which can break when another faction's pawn uses it. I'm yet unsure what's the best way to fix the root issue.

Originally posted by @mibac138 in #739 (comment)