Extract paths out of util (#13182)

This PR extracts the definition of the various Zed paths out of `util`
and into a new `paths` crate.

`util` is for generic utils, while these paths are Zed-specific. For
instance, `gpui` depends on `util`, and it shouldn't have knowledge of
these paths, since they are only used by Zed.

Release Notes:

- N/A

crates/fs/src/fs.rs

@@ -23,7 +23,7 @@ use std::{
 };
 use tempfile::{NamedTempFile, TempDir};
 use text::LineEnding;
-use util::{paths, ResultExt};
+use util::ResultExt;
 
 #[cfg(any(test, feature = "test-support"))]
 use collections::{btree_map, BTreeMap};