Restrict neighbor messages processing when sync

[kamilsa]

Referenced issues

When KAGOME observes neighbor message we do the following:

1. Update state of remote peer about their most recent round
2. Send them our current state (our round number)
3. If we identify that remote peer is far in the future by the finalized block, we send justification sync request.

2 and 3 is redundant if our node has never been synchronized (for example during fast sync).

Description of the Change

• We only start sending our neighbor messages (with our state) and justification sync requests only when we synchronized at least once.
• In addition to that we are fixing bufferization of stdout/stderr for Zombienet integration #1595 (not related to the main fix in PR)

Benefits

Less bandwidth

Possible Drawbacks

None