Rename worktree crate to project, pull in Project

Also, move the high-level fuzzy mathcing functions in
zed::fuzzy into the fuzzy crate so that project can
use them.

This required defining a 'PathMatchCandidateSet' trait
to avoid a circular dependency from fuzzy to worktree.

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

crates/zed/src/test.rs

@@ -12,9 +12,9 @@ use buffer::LanguageRegistry;
 use futures::{future::BoxFuture, Future};
 use gpui::MutableAppContext;
 use parking_lot::Mutex;
+use project::fs::FakeFs;
 use rpc_client as rpc;
 use std::{fmt, sync::Arc};
-use worktree::fs::FakeFs;
 
 #[cfg(test)]
 #[ctor::ctor]