Get DLA running balance per director

Returns the running DLA balance for each active director. A positive balance is overdrawn (the director owes the company), a negative balance is in credit (the company owes the director), and the status field names which. The aggregated balance adds the balances of connected persons into the primary director's figure for S455. Each entry flags whether S455 applies and whether the balance is above the Benefit in Kind threshold; the S455 charge is shown at the rate in force at the valuation date, returned in the response.