Snap sync UTXO set

[kiltsonfire]

Rationale

We need to be able to do snap sync in a way that allows us to download the UTXO sets that are using Muhash as the commitment which is not subject to griefing.

https://x.com/MichaelSuttonIL/status/1852126341392667092

Implementation

To do this we will need the following:

1. Nodes that periodically stop processing, to allow them to create a set proof for the snap sync point

• This will be a set of muhashes that hash into the commitment of the utxo set made in the block

2. A way for these set proofs to be disseminated to other nodes and have these node run the validation calculation and then make it available to anyone that asks iff it is a valid set proof
3. A way to get a set proof from a peer
4. Download chunks specified in the set proof when snap syncing any of the utxo sets.

If a peer provides a bad set proof they should be banned. If a peer provides a bad chunk of the set they should be ban.