Chargers quarterback Justin Herbert and his girlfriend, singer Madison Beer, had a fun night out with his teammates and their significant others on Saturday at the team’s Halloween party in West Hollywood. The couple, who first sparked dating rumors over the summer, coordinated in matching sailor costumes, as seen in photos obtained by The Post. Herbert, 27, and Beer, 26, showed off some PDA while posing in a photo booth with Chargers wide receiver Keenan Allen and his wife, CiMo Allen, as seen