Last night, as the drizzle gently fell on the West End pavements, I walked out of the Adelphi Theatre feeling spellbound, uplifted, and wrapped in a soft haze of theatrical magic. Speakeasy, the new dance production by Strictly Come Dancing stars Karen Hauer and Gorka Márquez, is more than a dance show – it’s an intoxicating time-travelling journey through the rhythms, moves, and moods of…