Fix wasi-sockets tests (#2389)

Tests were failing because the right permissions were not provided to iwasm.
Also, test failures didn't trigger build failure due to typo - also fixed in this change.

In addition to that, this PR fixes a few issues with the test itself:
* the `server_init_complete` was not reset early enough causing the client to occasionally
  assume the server started even though it didn't yet
* set `SO_REUSEADDR` on the server socket so the port can be reused shortly after
  closing the previous socket
* defined receive-send-receive sequence from server to make sure server is alive at the
  time of sending message

core/iwasm/libraries/lib-socket/test/nslookup.c

@@ -46,6 +46,7 @@ test_nslookup_mt(void *params)
 {
     int *af = (int *)params;
     test_nslookup(*af);
+    return NULL;
 }
 
 int