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)

Data/system_sources/location.svg

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   height="16"
+   viewBox="0 -960 640 640"
+   width="16"
+   fill="#e8eaed"
+   version="1.1"
+   id="svg1"
+   sodipodi:docname="location.svg"
+   inkscape:version="1.4 (e7c3feb100, 2024-10-09)"
+   inkscape:export-filename="location.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <defs
+     id="defs1" />
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#505050"
+     bordercolor="#eeeeee"
+     borderopacity="1"
+     inkscape:showpageshadow="0"
+     inkscape:pageopacity="0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:zoom="47.5"
+     inkscape:cx="12"
+     inkscape:cy="12"
+     inkscape:window-width="2560"
+     inkscape:window-height="1368"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg1" />
+  <path
+     d="M 347.36841,-361.6842 259.36842,-579.36842 41.684211,-667.36841 V -710.5965 L 597.47368,-917.47368 390.59649,-361.6842 Z m 20.07018,-114.24563 125.05263,-336.5614 -336.5614,125.05264 151.29825,60.21052 z m -60.21052,-151.29824 z"
+     id="path1"
+     style="stroke-width:0.771924" />
+</svg>