Adding Wefax demodulation mode inside Audio App (#2539)

* Adding_new_WFAX_GUI_mode_Audio_App

* Wefax_APT_demodulation_structure

* Solving REC Apt signal.wav from WFAX

* clang format issues

* correcting comments

firmware/baseband/dsp_demodulate.hpp

@@ -23,6 +23,7 @@
 #define __DSP_DEMODULATE_H__
 
 #include "dsp_types.hpp"
+#include "dsp_hilbert.hpp"
 
 namespace dsp {
 namespace demodulate {
@@ -47,6 +48,17 @@ class SSB {
     static constexpr float k = 1.0f / 32768.0f;
 };
 
+class SSB_FM {  // Added to handle WFAX-
+   public:
+    buffer_f32_t execute(
+        const buffer_c16_t& src,
+        const buffer_f32_t& dst);
+
+   private:
+    static constexpr float k = 1.0f / 32768.0f;
+    dsp::Real_to_Complex real_to_complex;  // It is a member variable of SSB_FM.
+};
+
 class FM {
    public:
     buffer_f32_t execute(