improve top holders by returning back additional details

it would be useful to improve top-holders endpoint to return back total counts, such as number of pages and results (accounts) found, similar to how other endpoints do, for example in the case of balance-history (totals, and then actual data inside a JSON array - see below). This is helpful to properly paginate and display record count on the UI.

{"total_operations":4700109,"total_pages":2350055,"operations_result":[{"block_num":99662602,"operation_id":"428047616224271680","op_type_id":64,"balance":"22691157033541080","prev_balance":"22691156521692512","balance_change":"511848568","timestamp":"2025-09-22T22:16:51"}]}