Ansa works in a Helsinki supermarket, collecting expired food and cadging the odd casserole for her dinner. Holappa is a laborer, working on scrap metal yards and construction sites. As they drift through their days, these two solitary, anonymous souls couldn’t be more banal. Or more captivating. In “Fallen Leaves,” the latest straight-faced serio-comedy from writer-director Aki Kaurismäki, Ansa and Holappa have all the makings of the kind of dispassionate, highly stylized, quietly operatic love stories only the Finnish master of deadpan romance can make.