feat: new sway-mode module (#671)

* feat: add sway-mode module

* refactor: Avoid making multiple connections to SwayIPC

Now `sway::Client` is store in `ironbar.clients`, and allow dynamically
registering event listeners, instead of hardcoding events for Workspace
updates.

Remove the use of `swayipc::Connection` from `sway-mode` module, and
replace it with the new event listener system.

#671

src/modules/mod.rs

@@ -41,6 +41,8 @@ pub mod networkmanager;
 #[cfg(feature = "notifications")]
 pub mod notifications;
 pub mod script;
+#[cfg(feature = "sway")]
+pub mod sway;
 #[cfg(feature = "sys_info")]
 pub mod sysinfo;
 #[cfg(feature = "tray")]