[Proof] Implement scalable proof validation

proto/poktroll/proof/event.proto

@@ -43,3 +43,11 @@ message EventProofUpdated {
   uint64 num_estimated_compute_units = 5 [(gogoproto.jsontag) = "num_estimated_compute_units"];
   cosmos.base.v1beta1.Coin claimed_upokt = 6 [(gogoproto.jsontag) = "claimed_upokt"];
 }
+
+// Event emitted after a proof has been checked for validity.
+message EventProofValidityChecked {
+  poktroll.proof.Proof proof = 1 [(gogoproto.jsontag) = "proof"];
+  uint64 block_height = 2 [(gogoproto.jsontag) = "block_height"];
+  poktroll.proof.ClaimProofStatus proof_status = 3 [(gogoproto.jsontag) = "proof_status"];
+  string reason = 4 [(gogoproto.jsontag) = "reason"];
+}

proto/poktroll/proof/types.proto

@@ -29,6 +29,9 @@ message Claim {
   poktroll.session.SessionHeader session_header = 2;
   // Root hash returned from smt.SMST#Root().
   bytes root_hash = 3;
+  // Claim proof status captures the status of the proof for this claim.
+  // WARNING: This field MUST only be set by proofKeeper#EnsureValidProofSignaturesAndClosestPath
+  ClaimProofStatus proof_status = 4;
 }
 
 enum ProofRequirementReason {
@@ -43,3 +46,11 @@ enum ClaimProofStage {
   SETTLED = 2;
   EXPIRED = 3;
 }
+
+// ClaimProofStatus defines the status of the proof for a claim.
+// The default value is NOT_FOUND, whether the proof is required or not.
+enum ClaimProofStatus {
+  NOT_FOUND = 0;
+  VALID = 1;
+  INVALID = 2;
+}

testutil/testtree/tree.go

@@ -152,5 +152,6 @@ func NewClaim(
 		SupplierOperatorAddress: supplierOperatorAddr,
 		SessionHeader:           sessionHeader,
 		RootHash:                rootHash,
+		ProofStatus:             prooftypes.ClaimProofStatus_NOT_FOUND,
 	}
 }