While we might never be able to have 100% of our code strict, we can at
the very least do it for all of our tests. This ensures that our tests
are using our API with the types as intended by the test author, and not
silently be cast to what our API requires.
Current implementation for all methods that take a single cell reference argument:
- `setCellValue()`
- `setCellValueExplicit()`
- `getCell()`
- `cellExists()`
- `setBreak()`
- `freezePane()`
- `getComment()`
Also introducing a CellRange object to work with similar cases for methods that accept a cell range rather than simply a cell address; and RowRange/ColumnRange objects for those cases.
Still need to apply to methods that accept a cell range or single cell:
- `mergeCells()`
- `unmergeCells()`
- `protectCells()`
- `unprotectCells()`
- `setAutoFilter()`
Then there's a few special cases that accept row and column ranges, not simply cell ranges; or a series of cell ranges.