[1.0-beta3 -> main] P2P: Set peer_syncing_from_us to false when a recent block is received

[heifner]

A node will set peer_syncing_from_us to false on a request_message of none or if it receives a handshake indicating it is synced. This PR sets peer_syncing_from_us to false if a node receive a recent block from the network as blocks are only relayed after they are validated. Therefore, if we receive a recent block from a peer we know that peer can't be syncing from us even if they have failed to send us a handshake letting us know they are up to date.

Merges release/1.0-beta3 into main including #315 & #317

Resolves #302

[ericpassmore]

Note:start
group: STABILITY
category: INTERNALS
summary: Add cases where we update peer syncing status to more accurately reflect peer syncing from us status.
Note:end