Airband VOR receiver and trasmitter (#3244)

* First test

* Reorder includes for consistency and fix string dereference in VorCdiIndicator

* Add memory section and linker script entry for vor_rx application

* Testing VOR TX

* Moving VOR TX to SD

* Code refactoring to align with guidelines

* Add TODO comment to verify radial sign convention in vor_tx_config

* Remove unnecessary set_dirty() calls in VorRxView methods

* Update Course Deviation Indicator label and adjust UI element positions

* Update VorTxView to run prepared image from memory map

* Update build condition in nightly release workflow to include workflow_dispatch event

* Reverting action changes

* Adjust Course Deviation Indicator layout and refine painting logic

* Refactor VorRxView UI elements for improved layout and clarity

* Add calibration field and update radial calculation logic in VorRxView

* Enhance VOR processing: add renormalization to phase oscillator, improve signal handling, and update configuration parameters

* Implement radial smoothing and TO/FROM state handling in VorRxView; update VOR processing logic

* Setting comments inline

* Refactor VorCdiIndicator and VorRxView: change normalize_signed_degrees to use int32_t, update radial smoothing to use fixed point arithmetic to reduce flash usage

* Update external app address end to 0xAE0B0000

* Update set_vor_tx_config to include enabled parameter for consistency

* Refactor VorRx to omit decim_2 stage and update comments for clarity on VOR processing

* Add RSSI, Channel, and Audio fields to VorRxView to mimic existing apps

* Refactor VorRxView labels and status messages

* Update VorRxView calibration field range to allow full circle input

* Completing Ident transmission logic

* Fixing TX gain and moving log label

* Refactor VOR phase calculations and update radial offset handling for accurate bearing representation

* Add low-pass filters to strip 9960 Hz subcarrier from audio output

firmware/common/dsp_iir_config.hpp

@@ -119,4 +119,12 @@ constexpr iir_biquad_config_t apt_audio_12k_lpf_2000hz_config{
     {0.15505103f, 0.31010205f, 0.15505103f},
     {1.00000000f, -0.6202041f, 0.24040821f}};
 
+// scipy.signal.butter(2, 3200 / 24000.0, 'low', analog=False)
+// VOR RX audio low-pass. Removes the 9960 Hz FM subcarrier (the annoying
+// high-pitch whine) while passing voice and the 1020 Hz ident tone. Cascade
+// two of these sections for a 4th-order roll-off (~44 dB at 9960 Hz).
+constexpr iir_biquad_config_t audio_48k_lpf_3200hz_config{
+    {0.03357181f, 0.06714362f, 0.03357181f},
+    {1.00000000f, -1.41898265f, 0.55326989f}};
+
 #endif /*__DSP_IIR_CONFIG_H__*/