Added "test app" as a draft zone for... stuff

Added second signature for M2K2 radiosonde

firmware/common/message.hpp

@@ -97,6 +97,7 @@ public:
 		POCSAGPacket = 50,
 		ADSBFrame = 51,
 		AFSKData = 52,
+		TestAppPacket = 53,
 		
 		RequestSignal = 60,
 		FIFOData = 61,
@@ -390,6 +391,18 @@ public:
 	baseband::Packet packet;
 };
 
+class TestAppPacketMessage : public Message {
+public:
+	constexpr TestAppPacketMessage(
+		const baseband::Packet& packet
+	) : Message { ID::TestAppPacket },
+		packet { packet }
+	{
+	}
+
+	baseband::Packet packet;
+};
+
 class UpdateSpectrumMessage : public Message {
 public:
 	constexpr UpdateSpectrumMessage(