network: update syncQueue to track sent/received requests by hash

[noot]

Task summary

• currently, the syncQueue tracks requests by number, not hash
• this is fine when syncing the chain, but at the head, we want to request blocks by hash since there are small chain forks
• currently we only request blocks by hash when needing to get a parent block we don't currently have
• update syncQueue to produce and track requests by hash as well as number

[EclesioMeloJunior]

Hi! The requests are blocks that we send to or receive from others peers? And track means to save at database?

[noot]

@EclesioMeloJunior hey, yes the requests are BlockRequestMessage s that we sent to other peers, we don't track requests that we receive. to track means to cache it in the syncQueue struct, for example, this is the current mapping used which tracks request info by starting number: https://github.com/ChainSafe/gossamer/blob/development/dot/network/sync.go#L130 the idea of this issue is to have the same mapping but for hashes, and use that when we request using StartingBlock as a hash, since StartingBlock can be a number or a hash: https://github.com/ChainSafe/gossamer/blob/development/dot/network/message.go#L71

[EclesioMeloJunior]

@noot, what is the use case of justificationRequestData? Can we use it when we request using StartingBlock as a hash?

[noot]

@EclesioMeloJunior hey, the justificationRequestData is for making requests that only request the justification, not the header + body + justification. so there should be a separate map for requests that are by hash that request header + body + justification

[EclesioMeloJunior]

closed with PR #1575