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

Cargo.lock

@@ -12790,7 +12790,6 @@ dependencies = [
  "feedback",
  "file_finder",
  "fs",
- "fsevent",
  "futures 0.3.28",
  "go_to_line",
  "gpui",