PROVIDENCE — Since Haven Brothers Diner rolled up Fulton Street pulled by horses in 1893, it has become a fixture of the Providence food scene.“I think that it’s a Rhode Island landmark,” said Tom Field, who was taking orders inside the nation’s oldest food truck Sunday. “It’s very nostalgic because not many things have stood the test of time.”The sit-in diner on wheels celebrated its 125th anniversary Sunday with music, [...]