Introduce blockStartingTxNoncesQuery

[OnedgeLee]

특정 블록 실행 전의 논스값들을 가져올 수 있는 쿼리를 추가합니다.

• Arguments로서는 블록의 hash 혹은 index 둘 중의 하나를 받아,
  • 해당 블록이 실행되기 이전의 해당 블록에 포함된 트랜잭션 서명자들에 대한 논스값을 리턴하며,
  • 만약 hash와 index 양 쪽 모두 기입하지 않을 경우, tip에 대하여 위의 논스값들을 리턴합니다.

[Copilot]

Pull Request Overview

Add a new GraphQL query to fetch starting transaction nonces for each signer in a specified block (by hash or index) or the tip if no arguments are provided.

• Define blockStartingTxNoncesQuery with hash/index arguments and fallback to tip
• Create BlockStartingTxNoncesType to map signer/nonces tuples
• Add a unit test covering the hash-based case

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
NineChronicles.Headless/GraphTypes/StandaloneQuery.cs	Add blockStartingTxNoncesQuery field with argument parsing and resolve logic
NineChronicles.Headless/GraphTypes/BlockStartingTxNoncesType.cs	Define GraphQL type for (Address Signer, long Nonce) tuples
NineChronicles.Headless.Tests/GraphTypes/StandaloneQueryTest.cs	Implement test for the new query when called with a block hash

Comments suppressed due to low confidence (2)

NineChronicles.Headless/GraphTypes/StandaloneQuery.cs:603

• [nitpick] The error message could be clearer. For example: "Provide either 'hash' or 'index', but not both."

=> throw new ArgumentException("Only one of 'hash' and 'index' must be given."),

NineChronicles.Headless.Tests/GraphTypes/StandaloneQueryTest.cs:779

• Coverage currently only tests the hash argument case. Consider adding tests for the index parameter and the default (no-argument) tip case to fully exercise the new query.

[Fact]

[Copilot]

Pull Request Overview

This PR introduces a new GraphQL query, blockStartingTxNoncesQuery, to retrieve the starting transaction nonces for a given block before execution. Key changes include:

• Adding the new query to StandaloneQuery.cs with tuple-based input handling.
• Creating a new GraphQL object type for block starting transaction nonces.
• Implementing tests in StandaloneQueryTest.cs to verify the query returns the expected nonce grouping.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
NineChronicles.Headless/GraphTypes/StandaloneQuery.cs	Introduces the blockStartingTxNoncesQuery with input validation and grouping logic.
NineChronicles.Headless/GraphTypes/BlockStartingTxNoncesType.cs	Defines the GraphQL type used by the new query.
NineChronicles.Headless.Tests/GraphTypes/StandaloneQueryTest.cs	Adds tests for the new query using the hash parameter.

Comments suppressed due to low confidence (1)

NineChronicles.Headless.Tests/GraphTypes/StandaloneQueryTest.cs:780

• [nitpick] Consider adding additional tests for scenarios when the query is called with the 'index' argument and when both 'hash' and 'index' are provided, to fully cover all input variations.

public async Task BlockStartingTxNonces()