Clean up `_path_path()` functions

[akrieger]

Summary

None

Purpose of change

Describe the solution

Replace string functions with path functions. Remove string functions. Rename path functions to shorter form previously occupied by string functions.

Describe alternatives you've considered

Testing

It compiles. I can write into the diary and it appears on disk in the right place. I die, and the game gets graveyarded correctly (or at least, the same as it was before. I think there's preexisting bugs). I can delete a world with active players inside and it deletes correctly.

Additional context

[akrieger]

Actually I can take care of them all.

[akrieger]

I am maybe not handling resetting a world correctly