It's impossible to get tickets to see Tom Hiddleston. But if the play's being staged to raise funds for Rada, why not be less elitist, and broadcast it in cinemas?The arts world is facing a Hamlet availability crisis. It is of course utterly impossible to get tickets for the reportedly superb Tom Hiddleston version of the play, running in a tiny London theatre for three weeks to raise money for the Royal Academy of D…