testing: add missing header files

Add missing header files in netutils and lsan modules to fix
implicit function declarations and improve compilation compatibility.

Signed-off-by: hongfengchen <hongfengchen@xiaomi.com>

.codespellrc

@@ -8,3 +8,6 @@ exclude-file = .codespell-ignore-lines
 # Ignore complete files (e.g. legal text or other immutable material).
 skip =
   LICENSE,
+
+# Ignore words list (FTP protocol commands and technical terms)
+ignore-words-list = ALLO

netutils/codecs/md5.c

@@ -53,6 +53,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <fcntl.h>
+#include <unistd.h>
 
 #include "netutils/md5.h"
 

netutils/ftpd/ftpd.c

@@ -48,6 +48,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <pthread.h>
 #include <unistd.h>
 #include <dirent.h>
 #include <strings.h>

system/lsan/lsan_main.c

@@ -26,6 +26,7 @@
 
 #include <nuttx/config.h>
 #include <stdio.h>
+#include <unistd.h>
 
 /****************************************************************************
  * Public Functions