Enable source debugging feature for windows platform (#910)

- use platform independent data types in debug-engine library
- add os_socket APIs and provide windows and posix implementation
- avoid using platform related header files in non-platform layer
- use format specifiers macros for sprintf and sscanf
- change thread handle type from uint64 to korp_tid
- add lock when sending socket packet to avoid thread racing

core/iwasm/libraries/debug-engine/utils.h

@@ -6,18 +6,18 @@
 #ifndef UTILS_H
 #define UTILS_H
 
-static const char hexchars[] = "0123456789abcdef";
+#include "bh_platform.h"
 
-int
+int32
 hex(char ch);
 
 char *
-mem2hex(char *mem, char *buf, int count);
+mem2hex(char *mem, char *buf, int32 count);
 
 char *
-hex2mem(char *buf, char *mem, int count);
+hex2mem(char *buf, char *mem, int32 count);
 
-int
-unescape(char *msg, int len);
+int32
+unescape(char *msg, int32 len);
 
 #endif /* UTILS_H */