Make soil albedo vary with soil water content

[imreddyTeja]

• [x] move PAR and NIR albedos to aux vars
• [x] add parameters for dry/wet albedo
• [ ] obtain default values for above params
• [x] update tests
• [ ] update any experiments, tutorials, simulations as needed
• [x] add support for PAR_albedo and NIR_albedo params and deprecate it