WS: Show received signal age (#2087)

* Feat: Show received signal age: by @LY2NEO with some fixes from me
* WS: Signal age display GUI fixes and improvements
* WeatherStation: refactor variable names
* WS: GUI fixes and improvements: add icons by @Karator and apply UI changes
* Weather Station: proper event flow for view redraw.

Co-authored-by: あく <alleteam@gmail.com>

applications/plugins/weather_station/protocols/ws_generic.h

@@ -29,6 +29,7 @@ struct WSBlockGeneric {
     uint8_t data_count_bit;
     uint8_t battery_low;
     uint8_t humidity;
+    uint32_t timestamp;
     uint8_t channel;
     uint8_t btn;
     float temp;