Add the ability to edit remote directories over SSH (#14530)

This is a first step towards allowing you to edit remote projects
directly over SSH. We'll start with a pretty bare-bones feature set, and
incrementally add further features.

### Todo

Distribution
* [x] Build nightly releases of `zed-remote-server` binaries
    * [x] linux (arm + x86)
    * [x] mac (arm + x86)
* [x] Build stable + preview releases of `zed-remote-server`
* [x] download and cache remote server binaries as needed when opening
ssh project
* [x] ensure server has the latest version of the binary


Auth
* [x] allow specifying password at the command line
* [x] auth via ssh keys
* [x] UI password prompt

Features
* [x] upload remote server binary to server automatically
* [x] opening directories
* [x] tracking file system updates
* [x] opening, editing, saving buffers
* [ ] file operations (rename, delete, create)
* [ ] git diffs
* [ ] project search

Release Notes:

- N/A

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>

crates/proto/src/proto.rs

@@ -18,7 +18,7 @@ use std::{
     fmt::{self, Debug},
     iter, mem,
     sync::Arc,
-    time::{Duration, Instant, SystemTime, UNIX_EPOCH},
+    time::{Duration, SystemTime, UNIX_EPOCH},
 };
 
 include!(concat!(env!("OUT_DIR"), "/zed.messages.rs"));
@@ -395,6 +395,9 @@ messages!(
     (UpdateContext, Foreground),
     (SynchronizeContexts, Foreground),
     (SynchronizeContextsResponse, Foreground),
+    // Remote development
+    (AddWorktree, Foreground),
+    (AddWorktreeResponse, Foreground),
 );
 
 request_messages!(
@@ -512,6 +515,8 @@ request_messages!(
     (RestartLanguageServers, Ack),
     (OpenContext, OpenContextResponse),
     (SynchronizeContexts, SynchronizeContextsResponse),
+    // Remote development
+    (AddWorktree, AddWorktreeResponse),
 );
 
 entity_messages!(