UUID filter

[kaworu]

Before this patch, it was not possible to find a flow by uuid.

% kubectl exec -it -n kube-system daemonset/cilium -c cilium-agent -- cilium version
Client: 1.14.0-snapshot.0 f917a797 2023-02-28T19:12:11-08:00 go version go1.20.1 linux/amd64
Daemon: 1.14.0-snapshot.0 f917a797 2023-02-28T19:12:11-08:00 go version go1.20.1 linux/amd64
% ./hubble observe -o json --first 10 | jq .flow.uuid
"8d4d4aa4-06bb-442e-9fc4-3d9348275fe6"
"7632dd97-c03c-4069-9cbd-744359e6818e"
"13f14953-3cb0-4046-bdd8-408ca6b45f6a"
"dbb2cc4f-8cbb-4d3f-9815-e2a159a657f6"
"26ca5fef-e07b-487a-930c-127ce5942bc6"
"b96c71fe-82c2-43e1-8ae7-68eb41e88f99"
"a7e679c7-fa1e-44b6-804e-100fac8dd13b"
"995217bd-2653-42c8-b580-171737d575d4"
"e02979f7-9f08-4cc5-8f5d-695b0510dc25"
"6141fef7-6a1f-4b63-9bd0-b0d46b5e8244"
% ./hubble observe -o json --uuid 6141fef7-6a1f-4b63-9bd0-b0d46b5e8244
{"flow":{"time":"2023-03-03T10:19:57.061196882Z","uuid":"6141fef7-6a1f-4b63-9bd0-b0d46b5e8244","verdict":"FORWARDED","ethernet":{"source":"36:32:78:1c:e6:1b","destination":"2e:51:86:7f:d1:b3"},"IP":{"source":"10.10.0.195","destination":"10.10.0.15","ipVersion":"IPv4"},"l4":{"TCP":{"source_port":59940,"destination_port":8181,"flags":{"ACK":true}}},"source":{"identity":1,"labels":["reserved:host"]},"destination":{"ID":3348,"identity":40675,"namespace":"kube-system","labels":["k8s:io.cilium.k8s.namespace.labels.kubernetes.io/metadata.name=kube-system","k8s:io.cilium.k8s.policy.cluster=alex","k8s:io.cilium.k8s.policy.serviceaccount=coredns","k8s:io.kubernetes.pod.namespace=kube-system","k8s:k8s-app=kube-dns"],"pod_name":"coredns-565d847f94-wfkk9","workloads":[{"name":"coredns","kind":"Deployment"}]},"Type":"L3_L4","node_name":"alex/alex-control-plane","event_type":{"type":4},"traffic_direction":"INGRESS","trace_observation_point":"TO_ENDPOINT","is_reply":false,"interface":{"index":13},"Summary":"TCP Flags: ACK"},"node_name":"alex/alex-control-plane","time":"2023-03-03T10:19:57.061196882Z"}

See also cilium/cilium#23638 for context.

[kaworu]

Converting to draft as I wish to wait on #913 to be merged (will probably conflict on cmd/observe_help.txt).

[chancez]

LGTM.

[sayboras]

LGTM on vendor changes ✔️