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/cli/src/main.rs

@@ -172,7 +172,6 @@ mod linux {
     use cli::FORCE_CLI_MODE_ENV_VAR_NAME;
     use fork::Fork;
     use once_cell::sync::Lazy;
-    use util::paths;
 
     use crate::{Detect, InstalledApp};