LE BOURGET, France—Six-time Ballon d’Or winner Lionel Messi received a hero’s welcome after flying to France on Tuesday to join Paris Saint Germain (PSG) following his shock departure from Barcelona. The agreement to sign the 34-year-old Argentine is a major coup for wealthy PSG, who will add one of the best soccer players of all time to an already formidable front line that includes Brazil’s Neymar and young Frenchman Kylian Mbappe. Wearing a T-shirt that read “This is Paris,” Messi beamed and waved at scores of fans who had come to greet him at Le Bourget airport on the outskirts of the French capital after his flight from Barcelona. Chanting “Messi, Messi, Messi,” the fans cheered and let off firecrackers. “It’s going to be mad. After all, it’s a legend who is arriving,” said Florent Chauveau, a PSG fan who has been back and forth to the airport every day …