Add rs-notify implementation of fs::watch (#9040)

This PR simplifies the Zed file system abstraction and implements
`Fs::watch` for linux and windows.

TODO:
- [x] Figure out why this fails to initialize the file watchers when we
have to initialize the config directory paths, but succeeds on
subsequent runs.
- [x] Fix macOS dependencies on old fsevents::Event crate

Release Notes:

- N/A

crates/zed/Cargo.toml

@@ -48,7 +48,6 @@ extensions_ui.workspace = true
 feedback.workspace = true
 file_finder.workspace = true
 fs.workspace = true
-fsevent.workspace = true
 futures.workspace = true
 go_to_line.workspace = true
 gpui.workspace = true