Extend SurfaceLayer for all boundary sides

[ckendrick]

This allows the MOST/Surface Layer boundary condition to be specified on all 6 faces instead of only zlo.

Main changes to SurfaceLayer/MOSTAverage classes:

• This adds a orientation parameter to the SurfaceLayer and MOSTAverage classes to determine behavior on different faces.
• MOST configuration options are prefixed with the face name if the SurfaceLayer BC type is specified on more than the zlo face (e.g, erf.most.surf_temp, can now be erf.xlo.most.surf_temp).
• MOST Averages and SurfaceLayer MultiFabs are constructed on planes corresponding to the face rather than at k=0.
• MOSTAverage is extended to compute averages of W and other planar velocities (XZ, YZ)
• MOSTAverage field ptrs are re-ordered from U/V/T/Qv/Qr/W to U/V/W/T/Qv/Qr.
• Local and regional averaging are supported, but not terrain interpolation, time windowing, EB, etc.
• SurfaceLayer writes to Tau and heat/moisture flux arrays for each face. Directional velocity averages and orientation is passed to MOSTStress.
• Only the Surface Temperature and Moeng flux pathway are updated for now to handle different faces.

Main changes to ERF:

• ERF now constructs a SurfaceLayer instance all 6 faces where the BC type is set to surface_layer (otherwise nullptr)
• Existing coupling dependent on reading surface layer values (SHOC, PBL, etc) should default to checking and reading on the zlo face only. Existing behavior on the zlo face should not be modified by these changes.
• X and Y hfx and qfx are read in the diffusion routines (N/S/T versions) from the surface layer on the face (if set).
• Each face writes its variables to checkpoint with a face index prefix ("UStar_0, UStar_1", etc). Existing checkpoints without a face prefix should be supported.

A follow-up PR will be made to adapt this for the new cloudchamber interface and problem configuration.