New GET accounts/{account_hash}/transactions endpoint

Daniel Marfurt; CFO of CasperLabs
Daniel needs to see historical transactions with a running balance for a given account with the block height, rewards received and staking transactions (Delegations and un-delegations) that have been made from an account over time.

The following endpoints can serve his needs:

Endpoint: **/accounts/{account_hash}/transactions**
Method: **GET**
Description: This endpoint retrieves historical transaction data for the specified account, including details about rewards received, staking transactions (delegations and un-delegations), and running balances. The response should provide a chronological list of transactions and their associated information.

Use the proposed GET /accounts/{account_hash}/transactions endpoint as the entry point and review existing account and transaction APIs before implementation. Done means the endpoint returns chronological historical transactions for the account, including block height, rewards, delegations, un-delegations, and running balances.

Written by the indexing model from the issue text.