Restructure remote client crate, consolidate SSH logic (#36967)

This is a pure refactor that consolidates all SSH remoting logic such
that it should be straightforward to add another transport to the
remoting system.

Release Notes:

- N/A

---------

Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>

crates/zed/src/reliability.rs

@@ -220,10 +220,10 @@ pub fn init(
         let installation_id = installation_id.clone();
         let system_id = system_id.clone();
 
-        let Some(ssh_client) = project.ssh_client() else {
+        let Some(remote_client) = project.remote_client() else {
             return;
         };
-        ssh_client.update(cx, |client, cx| {
+        remote_client.update(cx, |client, cx| {
             if !TelemetrySettings::get_global(cx).diagnostics {
                 return;
             }

crates/zed/src/zed.rs

@@ -918,7 +918,7 @@ fn register_actions(
             capture_audio(workspace, window, cx);
         });
 
-    if workspace.project().read(cx).is_via_ssh() {
+    if workspace.project().read(cx).is_via_remote_server() {
         workspace.register_action({
             move |workspace, _: &OpenServerSettings, window, cx| {
                 let open_server_settings = workspace
@@ -1543,7 +1543,7 @@ pub fn open_new_ssh_project_from_project(
     cx: &mut Context<Workspace>,
 ) -> Task<anyhow::Result<()>> {
     let app_state = workspace.app_state().clone();
-    let Some(ssh_client) = workspace.project().read(cx).ssh_client() else {
+    let Some(ssh_client) = workspace.project().read(cx).remote_client() else {
         return Task::ready(Err(anyhow::anyhow!("Not an ssh project")));
     };
     let connection_options = ssh_client.read(cx).connection_options();