Charing Cross theatre, London Carmel Owen's ambitious musical follows the impressionist's regrets back to his early adventures in art and his first marriage As its title suggests, this musical about Claude Monet is full of reflections " fittingly so given the artist's preoccupation with light. In 1916, while struggling to complete The Water Lilies with cataracts, the ageing painter (Jeff Shankley) retreats into memor…