NEW YORK—Prosecutors urged a judge Wednesday to impose a “very substantial” prison sentence on Michael Avenatti for trying to extort millions of dollars from Nike. Prosecutors noted in a Manhattan federal court submission that Probation Office officials recommend an eight-year prison term for the California attorney who gained fame three years ago through his representation of porn star Stormy Daniels against then-President Donald Trump. “The defendant, a prominent attorney and media personality with a large public following, betrayed his client and sought to enrich himself by weaponizing his public profile in an attempt to extort a publicly-traded company out of tens of millions of dollars. This was an egregious abuse of trust, and it warrants real and serious punishment,” prosecutors wrote. The government said Avenatti, representing the director of a youth basketball program in Los Angeles, tried to force the apparel maker to pay him up to $25 million to …