Add hooks to ip4 and ip6 output functions

[tp-qomodo]

Checklist

• Checked the issue tracker for similar issues to ensure this is not a duplicate.
• Described the feature in detail and justified the reason for the request.
• Provided specific use cases and examples.

Feature description

In LWIP there is currently hooks for the ip(x)_input functions which allow the app developer to view when packets are received and potentially filter them if required. I would like to propose an equivalent for the ip(x)_output functions so that an application developer is also able to view the packets that have been sent out, as well as potentially drop them before transmission.

Use cases

• Monitoring of network traffic produced by the device.
• Preventing unwanted outbound traffic.

Alternatives

No response

Additional context

An example solution for ip4 in ip4.c:1057 (in ip4_output_if_opt_src() - depending on project config)

#ifdef LWIP_HOOK_IP4_OUTPUT
err_t err = ERR_OK;
if ((err = LWIP_HOOK_IP4_OUTPUT(p, src, dest, ttl, tos, proto, netif, ip_options, optlen)) != ERR_OK)
{
  return err;
}
#endif

The user could then use ESP_IDF_LWIP_HOOK_FILENAME to include the definition of this macro.