Improved GPS Settings app and GPS service (#222)

- Fixes and improvements to `GpsSettings` app, `GpsDevice` and `GpsService`
- Implemented location/GPS statusbar icon
- Added app icon
- Added support for other GPS models (based on Meshtastic code)

TactilityHeadless/Include/Tactility/service/gps/GpsState.h

@@ -0,0 +1,12 @@
+#pragma once
+
+namespace tt::service::gps {
+
+enum class State {
+    OnPending,
+    On,
+    OffPending,
+    Off
+};
+
+}