v2.7.4: Named location presets and tappable nearest-airport ticker

Location presets can now optionally be given a name (e.g. "Home"),
shown in the overview instead of the raw coordinates. The
nearest-airport ticker on the Location Presets screen is now
tappable (shown with a thin green border) and adds that airport
directly as a new preset with its name and coordinates, using the
existing local airport database on the SD card - no internet lookup
needed. AirportLookup::findNearest() now also returns the found
airport's own lat/lon for this purpose.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/location_presets.h

@@ -8,10 +8,14 @@ namespace LocationPresets {
 
     uint8_t count();
     void getLatLon(uint8_t index, double& lat, double& lon);
+    // Vom Nutzer vergebener Name (z.B. "Zuhause") - leerer String, wenn
+    // keiner gesetzt wurde (dann zeigt der Screen stattdessen die
+    // Koordinaten an).
+    String getName(uint8_t index);
 
-    bool addPreset(double lat, double lon);
+    bool addPreset(double lat, double lon, const String& name = String());
     void removePreset(uint8_t index);
 
     int8_t activeIndex();
     void setActiveIndex(int8_t index);
-}
+}