Add a constant with the default value of 10000 and have the pathfinding settings refer to it.
Add a preventative method to AyStar when it's initializing, to limit the number of max_search_nodes if left unattended.
This reduced the load on compilers, as currently for example MacOS
doesn't like the huge settings-tables.
Additionally, nobody can find settings, as the list is massive and
unordered. By splitting it, it becomes a little bit more sensible.