By Chris Hayward The newly reelected Mayor is right to tout the merits of financial services. When the City succeeds, London succeeds, says Chris Hayward As Sadiq Khan returns to City Hall for an unprecedented third term as Mayor of London, this is a good moment to take stock of the challenges in the next four years, that we in the Square Mile and Greater London must overcome together. Foremost is cementing London’s place as a global powerhouse. We must continue to be a dynamic, thriving city that people and businesses want to call home. That requires an entire ecosystem built for success: goo…