[iota-rest-api] Add new endpoint to execute transaction for optimistic indexing purposes

[tomxey]

Created as a continuation of #5151

To ease introduction of optimistic indexing of transactions in indexer, we will require a new endpoint in the node that will execute a transaction and return all data required by the indexer.

The endpoint is meant to be called by the indexer, not the end users. The end users should still use the old endpoint.

Apart from normal tx execution response, the response should contain full transaction information in CheckpointTransaction format:

iota/crates/iota-types/src/full_checkpoint_content.rs

Line 77 in ae815a9

pub struct CheckpointTransaction {

The current standard execute_transaction_block endpoint (

iota/crates/iota-json-rpc/src/transaction_execution_api.rs

Line 141 in ce3b7f0

async fn execute_transaction_block(

) contains all necessary data (ExecuteTransactionResponseV1 and ExecuteTransactionRequestV1) to construct CheckpointTransaction.

The logic from execute_transaction_block can be a good base to create the new endpoint.

In case it would happen to be an issue, the response format could be based on

iota/crates/iota-rest-api/src/checkpoints.rs

Line 60 in f9fde1a

async fn get_checkpoint_full(

(which is returning CheckpointData, which contains CheckpointTransaction internally)