Use socket cookie for cgroup skb task context

[anjmao]

We are getting some invalid connection processes contexts when there is some server/client running on the same host and client connects to server. In such case socket may be cloned. Current logic of trying to find correct context form old socket doesn't always work.

This PR uses bpf socket storage map to store network task context.

[patrickpichler]

Awesome change,that simplifies quite a lot 🎉 🚀

As pointed out in one comment, investigating if sock storage could even further simplifies it, would be nice.