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/supermaven_api/Cargo.toml

@@ -16,7 +16,7 @@ doctest = false
 anyhow.workspace = true
 futures.workspace = true
 http.workspace = true
+paths.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 smol.workspace = true
-util.workspace = true