We want to be using forward slashes everywhere internally, so if we get a path from windows
we should immediately convert it to use forward slashes.
I'm leaving out the recent repos list because that would require a migration
There are quite a few paths you might want to get e.g. the repo's path, the worktree's path,
the repo's git dir path, the worktree's git dir path. I want these all obtained once and
then used when needed rather than having to have IO whenever we need them. This is not so
much about reducing time spent on IO as it is about not having to care about errors every time
we want a path.
