Support pathfinding avoiding sharp objects (barbed wire etc)

[jkraybill]

Summary

SUMMARY: Bugfixes "Avoid sharp things in player pathfinding"

Purpose of change

Fixes #37928 by preventing the player from auto-pathing into sharp things (barbed wire fences etc).

Describe the solution

I added a new pathfinding setting, to avoid sharp things, and set it to default true for the player and NPCs and false for monsters.

I made sharp items unpathable if avoid_sharp=true, because there is an issue with route_adjacent in activity_item_handling.cpp. In farming, route_adjacent is called. That method looks up the closest adjacent square to the target "to be planted" square, and if there is a valid path, regardless of cost, it will go to the first valid adjacent square. So I couldn't just give sharp objects a high cost, because path cost isn't taken into account in route_adjacent if the high-cost tile is the destination adjacent tile.

Describe alternatives you've considered

I considered just adding sharp-object-avoidance to the avoid_traps behaviour. This still seems like a reasonable alternative if there is going to never be a situation where pathfinding should avoid either traps or sharp things but not the other.

Testing

I did quite a lot of testing with pathfinding related to farming automation. I did not do a lot of testing related to non-farm-automation pathfinding.

Example of the types of setups I was testing:

Additional context

This is my second C++ commit of any significance, I've picked a couple doozies between fuel consumption and pathfinding. I would not be at all surprised if I have made some rookie mistakes and welcome all feedback.

I also expect, but have not confirmed, that this commit will fix some other annoyances with player auto-pathfinding into bushes and barbed wires.

[jkraybill]

Moving this to WIP because there's now some weird unintended behaviour in manual movement. Working on it.

[jkraybill]

Removed WIP tag, the test cases I was using are replicable in master with pit traps and auto-travel.

[jkraybill]

Did significantly more testing with overmap auto-move. This PR appears to fully resolve the "raspberry bush problem" at the expense of making raspberry bushes and other sharp objects effectively impassable terrain for automove. I think that's a good thing but it's entirely possible I have missed an edge case. This PR makes territory fully bordered by sharp objects un-navigable by auto-move, so if that causes problems I'm not aware of, please let me know.

[ghost]

Did significantly more testing with overmap auto-move. This PR appears to fully resolve the "raspberry bush problem" at the expense of making raspberry bushes and other sharp objects effectively impassable terrain for automove. I think that's a good thing but it's entirely possible I have missed an edge case. This PR makes territory fully bordered by sharp objects un-navigable by auto-move, so if that causes problems I'm not aware of, please let me know.

I think thats fine, automove shouldnt do anything risky or annoying, the player can do that themselves if they want to.

[jeremyshannon]

false for monsters.

I feel like that should only be false for unintelligent monsters like zombies or the blob. It's hard to have a pet dog right now when they routinely impale themselves on barbed wire and jagged wreckage because they won't path around it.

[jkraybill]

@jeremyshannon thanks for the tip. Opening a separate issue for that, this PR does add a JSON flag to allow that to be specified per monster.