longer segment names

* introducing WLED_MAX_SEGNAME_LEN from upstream
* default: max name length = 48
* hopefully found all places where the segment name length was hardcoded (32, 33, 34)
* some comments still refer to "32" but wtf

wled00/image_loader.cpp

@@ -5,11 +5,6 @@
 #include "GifDecoder.h"
 
 
-//upstream compatibility
-#if !defined(WLED_MAX_SEGNAME_LEN)
-#define WLED_MAX_SEGNAME_LEN 32
-#endif
-
 /*
  * Functions to render images from filesystem to segments, used by the "Image" effect
  */