Crossbody bags and roomy totes are consistent go-tos for celebrities — but we’ve also spotted A-listers carrying another practical style lately. It seems like shoulder bags are in for spring, since stars like Gisele Bündchen, Courteney Cox, Kirsten Dunst, and Heidi Klum have all donned the silhouette this season. They’ve proven that shoulder bags can be dressy or casual, pairing …