By Mitchell Forde While Derek Carr remains officially on the Las Vegas Raiders roster, his time with the team is effectively over. Carr posted a farewell message to the franchise he quarterbacked for nine seasons on social media Thursday after reports emerged that the Raiders had begun the process of trying to trade him. But before he left Las Vegas, Carr gave a very generous gift to two of his star teammates. According to Mick Akers of the Las Vegas Review-Journal, Carr had custom diamond pendants made for wide receiver Davante Adams and defensive end Maxx Crosby. The pendants, in silver and …