Summerhall, EdinburghIn its aim to avoid big topics " politics, gender, climate " the Canadian pair's superb show attempts an escape from contemporary chaos If the end of the world is a party, I want these two feral slugs to be our hosts. Fever-dreamed by Canadian clowning duo Creepy Boys, this absurd existential rave is brilliantly smart and beautifully stupid. Wriggling on to the stage in sleeping bags with puffy v…