The scene on stage at the Eurovision semifinals in Vienna this week has been the expected assemblage of cheesy love: Greece’s Akylas’ tiger-costumed ode to bling, Satoshi’s rappy anthem to Moldova (“aloha, adio, vida loca”), and, yes, Israel’s Noam Bettan’s French-Hebrew homage to his mythic Michelle. All three advanced to this weekend’s final. Behind the scenes, though, a scramble has been intensifying to hold together a fragile coalition politically and tenuous competition financially. If the effort fails, this could be the last viable year of the 70-year old mega-institution that is Eurovision. The  bold experiment in pop-culture unity — and birthplace of ABBA and Celine Dion — could be no more.…