Dynamic array support in NPOI

[drmason789]

In order to support the new dynamic arrays in Excel 365, NPOI would need to provide some sort of equivalents for these Range properties:

Formula2 Formula2R1C1 HasSpill SpillParent SpilingToRange SavedAsArray

The implicit intersection operator: @ The spilled range operator: #

Formula vs Formula2: https://docs.microsoft.com/en-us/office/vba/excel/concepts/cells-and-ranges/range-formula-vs-formula2

The formula evaluator would need to be upgraded to take dynamic arrays into account. Perhaps there should be an option somewhere to indicate if formulas should default to implicit intersection or dynamic array.

The functionality for getting the value of a cell would need to be upgraded to be aware if the cell is in the spilling range of a dynamic array spill parent and return the value accordingly.