Possibility to delete a zone#202

Adding the possibility to delete a zone (farm, fishing, mine,…) since the needs and building ideas can change overtime.

@DefensiveLeave296 This exists already! Delete all the tiles in your zone, and the tile with the sign will be last thing to delete. Once that’s done, the zone won’t exist!

Oh, I didn’t know as I tried without success. I’ll try again then, thanks !