GFX control, no-tokio, no-async, dbus client refactor

- Working gfx modes <iGPU only, dGPU only, or hybrid>
- Add signal for gfx vendor change and make CLI wait for signal
- Add polling for led brightness to save to config
- Move daemon to zbus crate
- dbus client refactor
- Further dbus methods and updates
- Add basic notification user daemon and systemd service

data/asus-notify.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=ASUS Notifications
+StartLimitInterval=200
+StartLimitBurst=2
+
+[Service]
+ExecStart=/usr/bin/asus-notify
+Restart=on-failure
+Restart=always
+RestartSec=1
+Type=simple
+
+[Install]
+WantedBy=default.target