Implement part of Berkeley Socket API for libc-wasi (#1036)

Refer to [Networking API design](https://github.com/WebAssembly/WASI/issues/370)
and [feat(socket): berkeley socket API v2](https://github.com/WebAssembly/WASI/pull/459):

- Support the socket API of synchronous mode, including `socket/bind/listen/accept/send/recv/close/shutdown`,
    the asynchronous mode isn't supported yet.
- Support adding `--addr-pool=<pool1,pool2,..>` argument for command line to identify the valid ip address range
- Add socket-api sample and update the document

core/shared/platform/windows/win_socket.c

@@ -152,3 +152,13 @@ os_socket_shutdown(bh_socket_t socket)
     shutdown(socket, SD_BOTH);
     return BHT_OK;
 }
+
+int
+os_socket_inet_network(const char *cp, uint32 *out)
+{
+    if (!cp)
+        return BHT_ERROR;
+
+    *out = inet_addr(cp);
+    return BHT_OK;
+}