Implement domain chain snap-sync

[shamil-gadelshin]

We need to implement domain chain snap sync similar to consensus chain snap sync to improve new domain operators UX by significantly increasing the initial sync speed.

Domain snap sync algorithm

1. Acquire the last confirmed domain block execution receipt from the consensus chain.
2. Use the consensus block number from the acquired execution receipt to snap sync the consensus chain.
3. Acquire the block for domain chain state sync (block number from the execution receipt - see 1.)
4. Download the domain state for the block acquired previously (3.)
5. Download MMR-data

Security concerns and implementation details

• consensus chain snap sync can't be applied directly to the domain chain because we must rely on the local consensus block production, this is why we produce the state block (3.) from the consensus block
• we implement a separate consensus algorithm for acquiring execution receipts (1.) similar to what we have for segment headers
• remote MMR data must be verified using state data (MMR roots) acquired differently
• synchronization is required to orchestrate different stages of the process split between consensus and domain chains: start consensus chain snap-sync after acquiring the execution receipt, pause consensus chain block production until domain state is acquired, etc.