Simplified LCR code a bit

Split modem into modem and serializer
Frequency string formatter

firmware/common/portapack_persistent_memory.cpp

@@ -23,7 +23,6 @@
 #include "portapack_persistent_memory.hpp"
 
 #include "portapack.hpp"
-
 #include "hal.h"
 
 #include "utility.hpp"

firmware/common/portapack_persistent_memory.hpp

@@ -28,8 +28,10 @@
 #include "rf_path.hpp"
 #include "touch.hpp"
 #include "modems.hpp"
+#include "serializer.hpp"
 
 using namespace modems;
+using namespace serializer;
 
 namespace portapack {
 namespace persistent_memory {