Check for and remove redundant variables for surface composite physics

[climbfuji]

There are potentially many variables that are redundant in the composite surface physics block, in a sense that there are now persistent variables and interstitial variables that hold the same information. The persistent data gets copied into the interstitial variables in GFS_surface_composite_pre, the interstitial variables get used in the surface iteration loop, and then copied back into the persistent arrays in GFS_surface_composite_post. Cleaning this up will reduce memory footprint, improve computational performance and make it easier to understand the code.

One example is surface_skin_temperature_over_land versus surface_skin_temperature_over_land_interstitial, another is the proliferation of ice temperature arrays.

If done correctly (i.e. if necessary update/reset the persistent arrays in GFS_surface_composite_pre to match the initialization of the interstitial arrays, similar to what was done in #596 for zorl), this will not change the answers.