The peer dropper periodically disconnects random peers to create churn.
This was previously blind to peer quality.
This PR adds peer-score based peer protection, handling the
multi-dimensionality problem of peer scoring through the concept of
protected peer pools.
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Signed-off-by: Csaba Kiraly <csaba.kiraly@gmail.com>
Co-authored-by: healthykim <bsbs8645@snu.ac.kr>
