Introduce a set of waiting peers

[takemiyamakoto]

Waiting peers are not participating in consensus - they are just syncing, and depending on the selection criteria might be selected as participating in consensus for the next epoch (epoch consists of several rounds) either randomly or through NPoS selection.

[takemiyamakoto]

RFC https://wiki.hyperledger.org/display/iroha/P2P+network

[s8sato]

Peers that do not participate in consensus, just sync new blocks. Another addition on top of that might be an archival node (one preserving many wsv snapshots)

Related to:

• [feature] Archival node #3527