New GET accounts/{account_hash}/transactions endpoint

[hectoratcasper]

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.