/block endpoint potential performance improvement

In Rosetta-TS
Something that I found for /block endpoint. If there are lot of transactions in a block, bigger than PAGE_SIZE. It does not get the entire transition data but only hash of the transaction under other_transactions . [ref](https://github.com/cardano-foundation/cardano-rosetta/blob/e61a396b4f0aad32feab52d7d99d75d6893d0cf4/cardano-rosetta-server/src/server/controllers/block-controller.ts#L44)

This not a feature in rosetta-java from what I searched on code. There are potential performance issue with /block transaction. So for large blocks, fetching just the transaction_hash would make it perform better as it will reduce the need to query for transaction body from different tables. Just throwing it here if it makes sense.