NewProcessor creates a new Processor.

ValidateMerkleRootsState merkle roots seq nums validation by comparing with on-chain state.

ConsensusObservation holds the consensus values for all chains across all observations in a round.

MerkleAggregatedObservation is the aggregation of a list of observations.

Processor is the processor responsible for reading next messages and building merkle roots for them, It's setup to use RMN to query which messages to include in the merkle root and ensures the newly built merkle roots are the same as RMN roots.