Create StateRecoveryDB and MessageRecoveryDB classes

[ishantiw]

Description

• Propose and define types for each data type, define getDBInstance to create DB instance. Below is one proposal,

// Data to be stored for state recovery
interface InclusionProof {
	height: number;
	stateRoot: Buffer;
	inclusionProof: OutboxRootWitness & { key: Buffer; value: Buffer };
	storeValue: Buffer;
	storeKey: Buffer;
}

interface ProofByHeight {
  Proof: Proof;
  Height: number
}

// Data to be stored for message recovery
interface CCMAndInclusionProofByHeight {
  ccms: CCM[];
  Proof: Proof;
  Height: number;
}

• Define DB classes for state and message recovery without implementation

class StateRecoveryDB {
	// Save proof by height
	public setInclusionProof(chainID, queryKey, proofByHeight) {}
	public getInclusionProof(chainID, queryKey) {}
      public getInclusionProofByHeight(height: number) {}
      public deleteInclusionProofsUntilHeight(height: number) {}
}

class MessageRecoveryDB {
	// Save CCMs and proof by height
	public setCCMs(chainID, CCMAndInclusionProofByHeight[]) {}
	public getCCMs(chainID) {}
}

Acceptance Criteria

• Should have all the files, interfaces and tests should be present

Additional Information

• Relevant implementation #8903