[Java] Use archiveId for looking up the RecordingPos counters.

[vyazelenko]

• Add a command to expose archiveId to the Archive control protocol.
• Add AeronArchive.archiveId().
• Use archiveId when searching for RecordingPos by recordingId and sessionId.

[mikeb01]

Should this be cached in AeronArchive?

[vyazelenko]

It is cached. See below.

[mikeb01]

Missed that. A style note, I personally like the early return approach for this sort of thing, e.g:

    if (Aeron.NULL_VALUE != archiveId)
    {
        return achiveId;
    }
        
    ensureOpen();
    ensureNotReentrant();

    lastCorrelationId = aeron.nextCorrelationId();

    if (!archiveProxy.archiveId(lastCorrelationId, controlSessionId))
    {
        throw new ArchiveException("failed to send get recorded length request");
    }

    archiveId = pollForResponse(lastCorrelationId);
    return archiveId;

Not required change for merging though.

[mikeb01]

Looks good to me.