apollo_gateway: move get_block_info to async

[itamar-starkware]

TL;DR

Made get_block_info in MempoolStateReader trait async to avoid blocking operations.

What changed?

• Modified the MempoolStateReader trait to make get_block_info an async function
• Updated implementations in RpcStateReader, SyncStateReader, and TestStateReader to be async
• Added #[async_trait] attribute to the trait and its implementations
• In RpcStateReader, moved the RPC request to a spawn_blocking task to prevent blocking the async runtime
• Removed the use of block_on in SyncStateReader in favor of proper async/await
• Updated all callers to use .await when calling get_block_info

How to test?

Run the existing tests which have been updated to use the async version of get_block_info:

• test_get_block_info in rpc_state_reader_test.rs
• test_get_block_info in sync_state_reader_test.rs

Why make this change?

This change improves the asynchronous behavior of the codebase by ensuring that potentially blocking operations like RPC requests don't block the async runtime. By making get_block_info async, we can properly handle I/O operations without blocking threads, which leads to better resource utilization and scalability.

[reviewable-StarkWare]

This change is 

[itamar-starkware]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• apollo_gateway: move get_block_info to async #10060 👈 (View in Graphite)
• apollo_gateway: move get_state_reader_from_latest_block to async #10059
• apollo_gateway: stateful_validator_factory::instantiate_validator to async #10058
• apollo_gateway: change ProcessTxBlockingTask::new to be async #10057
• main-v0.14.1

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