Low frequency RFID app [Read stage] (#385)

* App Lfrfid: init
* HAL-resources: add external gpios
* HAL-pwm: fix frequency calculation
* App LFRFID: generic manchester decoder
* App LFRFID: em-marine decoder
* App iButton: fix dwt timing acquire
* App LFRFID: rfid reader
* App LFRFID: temporary read keys on read scene
* App LFRFID: remove atomic bool init.
* App LFRFID: add *.c to build
* App LFRFID: unstable HID decoder
* App LFRFID: HID-26 reading
* HAL OS: disable sleep
* App LFRFID: HID-26 reader: remove debug
* App LFRFID: static data decoder-analyzer
* App LFRFID: very raw Indala decoder
* App LFRFID: multiprotocol reader
* App LFRFID: more reliable HID decoder
* App LFRFID: syntax fix
* App LFRFID: simple read scene
* Gui: force redraw on screen stream connect
* HAL-OS: allow sleep
* App LFRFID: notify api, tune view, tune scene
* App LFRFID: simple rfid emulator
* App LFRFID: more scenes, more reliable EM decoder.
* App LFRFID: format fix
* App LFRFID: warning fix
* Api-hal-resources: add rfid pins, rename external pins
* App LFRFID: remove unused emulator
* App LFRFID: use new gpio hal api
* App accessor: use new ext gpio name
* App LFRFID: remove unused emulator
* App LFRFID: remove debug gpio
* Api-hal-resources: alternate functions init
* Api-hal-rfid: new api
* Api-hal-ibutton: new api
* Api-hal: new headers
* App LFRFID: use new api in reader subroutines
* App LFRFID: use new api in emulator subroutines
* App LFRFID: remove old app
* App LFRFID, App iButton: fix memleak
* Api-hal-rfid: comments
* App LFRFID: pulse joiner helper, it combines pulses of different polarity into one pulse suitable for a timer
* App LFRFID: pulse joiner, now can accept only ne pulse
* App LFRFID: pulse joiner, fixes
* App LFRFID: EM encoder and emulation
* App LFRFID: format fixes
* App LFRFID: emmarine encoder cleanup
* App LFRFID: HID Encoder blank
* App LFRFID: Indala Encoder blank

applications/lf-rfid/helpers/manchester-decoder.h

@@ -0,0 +1,31 @@
+#pragma once
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+    ManchesterEventShortLow = 0,
+    ManchesterEventShortHigh = 2,
+    ManchesterEventLongLow = 4,
+    ManchesterEventLongHigh = 6,
+    ManchesterEventReset = 8
+} ManchesterEvent;
+
+typedef enum {
+    ManchesterStateStart1 = 0,
+    ManchesterStateMid1 = 1,
+    ManchesterStateMid0 = 2,
+    ManchesterStateStart0 = 3
+} ManchesterState;
+
+bool manchester_advance(
+    ManchesterState state,
+    ManchesterEvent event,
+    ManchesterState* next_state,
+    bool* data);
+
+#ifdef __cplusplus
+}
+#endif