Make WayVR IPC independent of the built-in Wayland server

- Rename state -> wayland_state
- Move WayVR IPC server outside "wayvr" (wayland server) feature
- WayVR IPC server is now available without "wayvr" (wayland server) feature
- Remove run_compositor_at_start (run wayland server instantly)

wlx-overlay-s/src/ipc/signal.rs

@@ -0,0 +1,19 @@
+#[cfg(feature = "wayvr")]
+use crate::backend::wayvr;
+
+#[derive(Clone)]
+pub enum WayVRSignal {
+    #[cfg(feature = "wayvr")]
+    DisplayVisibility(wayvr::display::DisplayHandle, bool),
+    #[cfg(feature = "wayvr")]
+    DisplayWindowLayout(
+        wayvr::display::DisplayHandle,
+        wayvr_ipc::packet_server::WvrDisplayWindowLayout,
+    ),
+    #[cfg(feature = "wayvr")]
+    BroadcastStateChanged(wayvr_ipc::packet_server::WvrStateChanged),
+    #[cfg(feature = "wayvr")]
+    Haptics(crate::backend::input::Haptics),
+    DropOverlay(crate::windowing::OverlayID),
+    CustomTask(crate::backend::task::ModifyPanelTask),
+}