Use test case for new Grid and SparseMatMul

Develop a use test case using the new Grid structures and the enhanced Array SparseMatMul routine that illustrates how to interpolate between two grids using the Array class SparseMatMul routines. We are proposing targeting a WRF and HYCOM coupling. The custom weights needed for the Array SparseMatMul calls will be provided externally using the I/O capability currently in use in the original SparseMatMul Use Test Case. This I/O capability will be improved as time allows.