Focus on toggle dock (#2612)

This PR updates some dock behaviors. Now the toggle-dock commands
(cmd-j/b/r) also toggle focus. This also adds zoom serialization to the
docks.

Release Notes:
- Bug fix: Toggle dock commands (cmd-j/b/r) now move focus 
- Bug fix: Dock zoom is now restored with the rest of the workspace

crates/zed/src/zed.rs

@@ -384,6 +384,8 @@ pub fn initialize_workspace(
                 workspace.toggle_dock(project_panel_position, cx);
             }
 
+            cx.focus_self();
+
             workspace.add_panel(terminal_panel, cx);
             if let Some(assistant_panel) = assistant_panel {
                 workspace.add_panel(assistant_panel, cx);