core: sort GetValidators() result

As C# node does it. Technically it's only needed for consensus and could be
implemented in the appropriate package, but for better compatibility with C#
node we're better returning it sorted right here.

pkg/consensus/consensus_test.go

@@ -194,23 +194,24 @@ func newTestService(t *testing.T) *service {
 func getTestValidator(i int) (*privateKey, *publicKey) {
 	var wif, password string
 
+	// Sorted by public key.
 	switch i {
 	case 0:
-		wif = "6PYLmjBYJ4wQTCEfqvnznGJwZeW9pfUcV5m5oreHxqryUgqKpTRAFt9L8Y"
-		password = "one"
-
-	case 1:
 		wif = "6PYXHjPaNvW8YknSXaKsTWjf9FRxo1s4naV2jdmSQEgzaqKGX368rndN3L"
 		password = "two"
 
-	case 2:
-		wif = "6PYX86vYiHfUbpD95hfN1xgnvcSxy5skxfWYKu3ztjecxk6ikYs2kcWbeh"
-		password = "three"
-
-	case 3:
+	case 1:
 		wif = "6PYRXVwHSqFSukL3CuXxdQ75VmsKpjeLgQLEjt83FrtHf1gCVphHzdD4nc"
 		password = "four"
 
+	case 2:
+		wif = "6PYLmjBYJ4wQTCEfqvnznGJwZeW9pfUcV5m5oreHxqryUgqKpTRAFt9L8Y"
+		password = "one"
+
+	case 3:
+		wif = "6PYX86vYiHfUbpD95hfN1xgnvcSxy5skxfWYKu3ztjecxk6ikYs2kcWbeh"
+		password = "three"
+
 	default:
 		return nil, nil
 	}

pkg/core/blockchain.go

@@ -1413,6 +1413,7 @@ func (bc *Blockchain) GetValidators(txes ...*transaction.Transaction) ([]*keys.P
 			result = append(result, uniqueSBValidators[i])
 		}
 	}
+	sort.Sort(result)
 	return result, nil
 }