refactor / cleanup font selection logic

* centralize font selection logic into  getFontInfo()
* removed unneeded parameter "numberOfChars" from drawText()
* new file: wled_fonts.hpp to centralize font management logic (inline)
* only compile wchar16ToCodepage437 when WLED_ENABLE_FULL_FONTS
* minor cleanup

wled00/src/font/codepage437.cpp

@@ -1,5 +1,3 @@
-#if defined(WLED_ENABLE_FULL_FONTS)
-
 /* 
    @title     WLED(-MM) - unicode to CP437 conversion
    @repo      https://github.com/MoonModules/WLED-MM, https://github.com/wled/WLED
@@ -7,6 +5,8 @@
    @license   Licensed under the EUPL-1.2 or later
 */
 
+#if defined(WLED_ENABLE_FULL_FONTS)
+
 #include "codepages.h"
 #include <string.h>