Add name-based information to container info

[hillu]

The following bits of information require talking to a container runtime. They require #97 to be resolved.

• image
• name
• pod_uid
• pod_name
• pod_namespace

[n9]

Since #97 (async/await) is abandoned what about using two threads:

• The first thread will read auditd records from the stdin (and maybe do some simple preprocessing / filtering?) and push the records (or already combined laurel events) into a queue (buffer).
• The second thread will read the queue and (if needed) do the blocking I/O (e.g. communication with containerd).

What do you think?

[hillu]

I'd really like to revisit asyc/await at some point. Since communication with containerd seems to require gRPC, using tonic seems to make most sense anyway.