Add string function to strip all SCC characters

src/string_func.h

@@ -48,6 +48,7 @@ void ValidateString(const char *str);
 
 const char *str_fix_scc_encoded(char *str, const char *last);
 void str_strip_colours(char *str);
+std::string str_strip_all_scc(const char *str);
 char *str_replace_wchar(char *str, const char *last, WChar find, WChar replace);
 bool strtolower(char *str);