[Core] Flow Tap tap-hold option to disable HRMs during fast typing (#25125)

aka Global Quick Tap, Require Prior Idle

quantum/action.h

@@ -128,6 +128,12 @@ void layer_switch(uint8_t new_layer);
 bool is_tap_record(keyrecord_t *record);
 bool is_tap_action(action_t action);
 
+/**
+ * Given an MT or LT keycode, returns the tap keycode. Otherwise returns the
+ * original keycode unchanged.
+ */
+uint16_t get_tap_keycode(uint16_t keycode);
+
 #ifndef NO_ACTION_TAPPING
 void process_record_tap_hint(keyrecord_t *record);
 #endif