socket enricher: add new fields: ppid, pcomm, exepath, cwd

[alban]

This patch adds new fields in the socket enricher. It is not used by any gadget yet, but it makes it possible to add the new fields in gadgets using the socket enricher.

How to use

If you want to make use of the new fields in your own gadget, you could write something like:

--- a/pkg/gadgets/trace/dns/tracer/bpf/dns.c
+++ b/pkg/gadgets/trace/dns/tracer/bpf/dns.c
@@ -234,8 +234,11 @@ int ig_trace_dns(struct __sk_buff *skb)
                event.mount_ns_id = skb_val->mntns;
                event.pid = skb_val->pid_tgid >> 32;
                event.tid = (__u32)skb_val->pid_tgid;
+               event.ppid = skb_val->ppid;
                __builtin_memcpy(&event.task, skb_val->task,
                                 sizeof(event.task));
+               __builtin_memcpy(&event.pcomm, skb_val->pcomm,
+                                sizeof(event.pcomm));
                event.uid = (__u32)skb_val->uid_gid;
                event.gid = (__u32)(skb_val->uid_gid >> 32);
        }

See PR #2684 for an example in the dns gadget.

Testing done

Let's check the CI.

[alban]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Gadget benchmarks'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 2.

Benchmark suite	Current: a38b673	Previous: ad488f3	Ratio
BenchmarkAllGadgetsWithContainers/container0/trace-dns	26879440 ns/op	8837005 ns/op	3.04
BenchmarkAllGadgetsWithContainers/container0/trace-network	19798211 ns/op	2265452 ns/op	8.74

This comment was automatically generated by workflow using github-action-benchmark.

CC: @alban