Changes for allowing Alexa to change light color to White when auto-calculating from RGB (#3211)

* Changes for allowing Alexa to change light color to White when auto-calculating from RGB

* Update alexa.cpp

Indention

* Do not rely on global auto white override

(gets white mode from segment light capabilities)

* alexa.cpp: Removed unnecessary whitespaces

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Co-authored-by: Aircoookie <21045690+Aircoookie@users.noreply.github.com>

wled00/FX.h

@@ -772,6 +772,7 @@ class WS2812FX {  // 96 bytes
       getActiveSegmentsNum(void),
       getFirstSelectedSegId(void),
       getLastActiveSegmentId(void),
+      getActiveSegsLightCapabilities(bool selectedOnly = false),
       setPixelSegment(uint8_t n);
 
     inline uint8_t getBrightness(void) { return _brightness; }