PHILADELPHIA — Bryce Harper had something to say. So, after being presented with the National League MVP award in a pregame ceremony Saturday, he stepped to a podium and made brief remarks, including eight words that may serve as the keynote to the Phillies’ season. “Let’s go have a party on Broad Street.” On cue, then, Nick Castellanos brought a noisemaker. Castellanos swatted his first Phillies home run, a two-run shot in the first inning after Harper got hit by a pitch. And like his power-hitting partner, Kyle Schwarber, 25 hours earlier on opening day, Castellanos’ blast set the tone for a…