It’s all about the youth in MLS in 2026, and Wednesday night’s slate offered an intense look at two of the names that could find their way into the next wave of U.S. soccer stars: Cavan Sullivan and Julian Hall.  While already enjoying several accolades through their young careers, the two teenagers made history on Wednesday.  For the 16-year-old Sullivan, who is bound for Manchester City once he turns 18, it marked his first MLS goal, making him the eighth-youngest player to score in an MLS regular-season match. Despite a lack of minutes this season, the youngster entered the game and instantly changed the match for the Philadelphia Union .  Entering in the 44th minute ahead of the halftime break, Sullivan was energetic throughout his performance, finding the net in the 75th minute of play, beating Orlando City ’s backstop and Canada’s likely World Cup starting goalkeeper, Maxime Crépeau, after making a perfect pass and run to the penalty spot for a first-touch finish.  Cavan Sullivan…