SNICAR-ADv4 enabled ELM bare ice albedo

Whicker et al, (2023) incorporated the new SNICAR-ADv4 bare ice radiative transfer model into ELM's current snow radiative transfer model and used MODIS measurements to inform the optically relevant bare ice physical properties. This release includes those modifications. To turn these code modifications on, set use_snicar_lndice = .true. in user_nl_elm