After nearly eight months in limbo, former President Donald J. Trump’s federal election interference case sprang back to life on Saturday as the judge overseeing it scheduled a hearing in Washington for Aug. 16 to discuss next steps.At the hearing, the judge, Tanya S. Chutkan, will discuss with Mr. Trump’s lawyers and prosecutors in the office of the special counsel, Jack Smith, how each side would like to proceed with a complicated fact-finding mission the Supreme Court ordered last month. The order was part of its landmark ruling granting Mr. Trump broad immunity against criminal prosecution for acts arising from...