new functions prototypes, minor fixes

* prototypes for UTF-8 ==> wchar16 conversion
* minor fixes

wled00/src/font/unicodetool.cpp

@@ -0,0 +1,17 @@
+#if defined(WLED_ENABLE_FULL_FONTS)
+
+#include "codepages.h"
+#include <string.h>
+
+// translates the next unicode UTF-8 item to 2-byte "code points" (reduced UTF-16)
+uint16_t unicodeToWchar16(const char* utf8, size_t maxLen) {
+  // to be implemented
+}
+
+// returns a pointer to the next unicode item - can be used to "advance" conversion after unicodeToWchar16()
+// return nullptr at end of input
+const char* nextUnicode(const char* utf8, size_t maxLen) {
+  // to be implemented
+}
+
+#endif