Setfreq usb command (#2235)

* SetFreq usb command for rx apps
* code format, better check

firmware/application/apps/capture_app.hpp

@@ -108,6 +108,15 @@ class CaptureAppView : public View {
         3};
 
     spectrum::WaterfallView waterfall{};
+
+    MessageHandlerRegistration message_handler_freqchg{
+        Message::ID::FreqChangeCommand,
+        [this](Message* const p) {
+            const auto message = static_cast<const FreqChangeCommandMessage*>(p);
+            this->on_freqchg(message->freq);
+        }};
+
+    void on_freqchg(int64_t freq);
 };
 
 } /* namespace ui */