Add messages for get_pending_nonce mempool RPC

[mvandeberg]

Brief description

Adds mempool RPC get_pending_nonce to return a pending nonce from the mempool if the payee has a transaction in the mempool.

Checklist

• I have built this pull request locally
• I have ran the unit tests locally
• I have manually tested this pull request
• I have reviewed my pull request
• I have added any relevant tests

Demonstration

❯ ./run.sh pending_nonce                               
~/dev/koinos-integration-tests/tests/pending_nonce ~/dev/koinos-integration-tests
[+] Running 6/6
 ✔ Network pending_nonce_default          Created                                                                                                                                                                                                     0.1s 
 ✔ Container pending_nonce-amqp-1         Started                                                                                                                                                                                                     0.2s 
 ✔ Container pending_nonce-chain-1        Started                                                                                                                                                                                                     0.3s 
 ✔ Container pending_nonce-block_store-1  Started                                                                                                                                                                                                     0.5s 
 ✔ Container pending_nonce-jsonrpc-1      Started                                                                                                                                                                                                     0.5s 
 ✔ Container pending_nonce-mempool-1      Started                                                                                                                                                                                                     0.5s 
=== RUN   TestPublishTransaction
    integration.go:699: Waiting 1s for chain to be ready...
    integration.go:699: Waiting 2s for chain to be ready...
    integration.go:699: Waiting 4s for chain to be ready...
--- PASS: TestPublishTransaction (7.04s)
PASS
ok      koinos-integration-tests/tests/pending_nonce    7.056s
[+] Running 6/6
 ✔ Container pending_nonce-jsonrpc-1      Removed                                                                                                                                                                                                     0.2s 
 ✔ Container pending_nonce-mempool-1      Removed                                                                                                                                                                                                     0.3s 
 ✔ Container pending_nonce-block_store-1  Removed                                                                                                                                                                                                     0.1s 
 ✔ Container pending_nonce-chain-1        Removed                                                                                                                                                                                                     0.3s 
 ✔ Container pending_nonce-amqp-1         Removed                                                                                                                                                                                                     1.2s 
 ✔ Network pending_nonce_default          Removed                                                                                                                                                                                                     0.2s 
~/dev/koinos-integration-tests

[sgerbino]

koinos-proto/koinos/chain/system_calls.proto

Lines 133 to 135 in 1afa227

	message get_account_nonce_arguments {
	bytes account = 1 [(btype) = ADDRESS];
	}

For consistency I think it's better to name this account.

[mvandeberg]

In the mempool RPC, we follow payee/payer distinctions. I was following what we were doing in the other mempool RPC calls.

koinos-proto/koinos/rpc/mempool/mempool_rpc.proto

Lines 17 to 22 in 1afa227

	message check_pending_account_resources_request {
	bytes payer = 1 [(btype) = ADDRESS];
	uint64 max_payer_rc = 2 [jstype = JS_STRING];
	uint64 rc_limit = 3 [jstype = JS_STRING];
	optional bytes block_id = 4 [(btype) = BLOCK_ID];
	}

koinos-proto/koinos/rpc/mempool/mempool_rpc.proto

Lines 37 to 41 in 1afa227

	message check_account_nonce_request {
	bytes payee = 1 [(btype) = ADDRESS];
	bytes nonce = 2;
	optional bytes block_id = 3 [(btype) = BLOCK_ID];
	}

[sgerbino]

Your logic is sound.