Make rainbow effects more colorful (#3681)

* Make color_wheel rotate in HSV sapce instead of linearly interpolating R->G->B
* Remove the rainbow wheel option, as that is the same as the rainbow palette
* Use hsv2rgb for color_wheel

This is the current result of the discussion in https://github.com/wled/WLED/pull/3681

wled00/set.cpp

@@ -351,7 +351,6 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
     t = request->arg(F("TP")).toInt();
     randomPaletteChangeTime = MIN(255,MAX(1,t));
     useHarmonicRandomPalette = request->hasArg(F("TH"));
-    useRainbowWheel = request->hasArg(F("RW"));
 
     nightlightTargetBri = request->arg(F("TB")).toInt();
     t = request->arg(F("TL")).toInt();