Function isEqualCells

isEqualCells(a: CellCoords | null, b: CellCoords | null): boolean
Check if two coords are equal.
Parameters
- a: CellCoords | null
  First CellCoords
- b: CellCoords | null
  Second CellCoords
Returns boolean

Remarks
CellCoords.scope (the sheet a coord lives on) is part of a coord's identity: the same row/col on two different sheets are NOT equal. Backward compatible — a coord with no scope compares unchanged against another with no scope (undefined === undefined).