Add damping model interface for 6-field shell theory (Reissner shell)
Add damping model interface for 6-field shell theory (Reissner shell)

Milad-Rakhsha/chrono,dariomangoni/chrono,rserban/chrono,dariomangoni/chrono,projectchrono/chrono,projectchrono/chrono,projectchrono/chrono,rserban/chrono,rserban/chrono,dariomangoni/chrono,dariomangoni/chrono,rserban/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,rserban/chrono,Milad-Rakhsha/chrono,dariomangoni/chrono,projectchrono/chrono,projectchrono/chrono,rserban/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,rserban/chrono,dariomangoni/chrono