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/workspace/src/tasks.rs

@@ -20,7 +20,7 @@ impl Workspace {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        match self.project.read(cx).ssh_connection_state(cx) {
+        match self.project.read(cx).remote_connection_state(cx) {
             None | Some(ConnectionState::Connected) => {}
             Some(
                 ConnectionState::Connecting