A traveller site in Essex, originally approved for just 50 caravans half a century ago, has ballooned into a sprawling encampment now thought to accommodate more than 1,500 residents largely including asylum seekers.Buckles Lane in South Ockendon was once tranquil green-belt land where horses roamed, but today is packed with hundreds of static homes, many in poor condition, occupied by migrant workers and individuals with criminal connections.An…