use video scaling instead of NPB luminance & new ABL (#4798)

* updated color scaling to preserve hue at low brightness resulting in much better colors
* replace NPBlg with NPB, moved brightness scaling to bus manager
* improved gamma table calculation: fixed mismatch in inverting gamma table calculation: inversion should now be as good as it gets
* code cleanup, fixed gamma being applied in unnecessary places

Improvements to ABL handling:
- removed strip level handling, ist now all done on bus level
- limiter now respects pixel mapping
- proper handling of white channel
- improved current estimation
- current is now always correctly reported to UI
- minimal FPS impact if the ABL is not limiting but slighly higher impact for global ABL limit due to double-scaling

- moved brightness scaling to BusDigital
- created new header file colors.h to be able to access color functions in bus-manager.
- updated colo_fade() with better video scaling to preserve hue's at low brightness
- added IRAM_ATTR to color_fade (negligible speed impact when compared to inline and benefits other functions)
- added IRAM_ATTR to color_blend as it is used a lot throughout the code, did not test speed impact but adding it to color_fade made it almost on-par with an inlined function

Additional changes:
- fixes for properly handling `scaledBri()` (by @blazoncek)
- also use bit-shift instead of division in blending for ESP8266
- improvements for faster "softlight" calculation in blending
- changed some variables to uint8_t to maybe let the compiler optimize better, uint8_t can be faster if read, store and set are all done in uint8_t, which is the case in the ones I changed
- various minor code formatting changes

wled00/wled.cpp

@@ -190,12 +190,10 @@ void WLED::loop()
     doInitBusses = false;
     DEBUG_PRINTLN(F("Re-init busses."));
     bool aligned = strip.checkSegmentAlignment(); //see if old segments match old bus(ses)
-    BusManager::removeAll();
     strip.finalizeInit(); // will create buses and also load default ledmap if present
-    BusManager::setBrightness(bri); // fix re-initialised bus' brightness #4005
     if (aligned) strip.makeAutoSegments();
     else strip.fixInvalidSegments();
-    BusManager::setBrightness(bri); // fix re-initialised bus' brightness
+    BusManager::setBrightness(scaledBri(bri)); // fix re-initialised bus' brightness #4005 and #4824
     configNeedsWrite = true;
   }
   if (loadLedmap >= 0) {