fix(crypto): include cstring for mem* usage

* Adds the missing standard header to ensure `mem*` functions are
  declared across toolchains and avoid build errors

Author: saturneric

src/core/function/AESCryptoHelper.cpp

@@ -30,6 +30,8 @@
 
 #include <sodium.h>
 
+#include <cstring>
+
 #include "core/function/SecureRandomGenerator.h"
 
 namespace {