PORTLAND, Ore. — The Pistons aren’t finished dealing just yet. Detroit general manager Troy Weaver negotiated three transactions on the morning of Thursday’s NBA trade deadline, including a deal to send sharpshooters Bojan Bogdanovic and Alec Burks to the New York Knicks in exchange for a package that includes Quentin Grimes, Malachi Flynn and two future second-round picks, the team announced. The Pistons have also added Evan Fournier and Ryan Arcidiacono from the Knicks in a separate deal. Bogdanovic and Burks were viewed as the Pistons’ most valuable veteran assets and they will remain in th…