Extend account API to provide additional details

As suggested in block_explorer_ui#492 , it might be worthy to add additional details into the hafbe account API to cover values including:

• open_recurrent_transfer
• pending_claimed_accounts
• governance_vote_expiration_ts
• withdraw_routes
• those 3 below maybe under a computed value like "pending hbd interest"
  • hbd_last_interest_payment
  • hbd_seconds
  • hbd_seconds_last_update