Fix issue entering pitmode.

Make as many variables as possible private.
Re-work settings application into state machine.
Remove legacy interfaces.
Update OSD interface following implementation rework.
Review updates.

src/main/build/debug.h

@@ -113,6 +113,7 @@ typedef enum {
     DEBUG_GYRO_SAMPLE,
     DEBUG_RX_TIMING,
     DEBUG_D_LPF,
+    DEBUG_VTX_TRAMP,
     DEBUG_COUNT
 } debugType_e;