Ambience Healthcare Inc., an artificial intelligence startup focused on streamlining administrative work for medical professionals, has raised $243 million in a new round of funding that values the company at more than $1 billion.The financing, set to be announced on Tuesday, was led by Andreessen Horowitz and investment firm Oak HC/FT. Earlier backers, including OpenAI’s startup fund, Kleiner Perkins and Optum Ventures, also participated....