OptionaltextWhether a text value is read as a typed entry is — 9/23/95 a date, 12.3% a number —
rather than taken as the text it is. true reads it with the defaults; an
ICell.ModifiersFromStringOptions customizes the reading.
The same reading ICellRange.setValues gives text, where it is the default. Here it is opt-in: a cell created from a value keeps that value.
Options for ICell.createCell and ISheet.createCell.