Fix#943, which went stale a long time ago, and is now reopened. I believe that the specific problem in that issue was actually mostly resolved some time ago. However, `highestRow/Column` produces questionable results when the delete range overlaps the highest row/column. That is fixed by this PR.
In addition, `removeRow/Column` allow the specification of a non-negative value for `numberOfRows/Columns`. But the expected results in those cases are not defined, and the actual results probably do not meet user expectations. I believe that very few, if any, users are taking advantage of this "feature", but we may as well straighten it out. For 0 rows/columns, I think it makes perfect sense to do nothing. As for negative - if `removeRow(5, 2)` says to remove 2 rows *starting* with 5, I think `removeRow(5, -2)` ought to remove (up to) 2 rows *ending* with 5. The undefined behaviors are changed to act as described in this paragraph.
We have identical constants defined in several places, and use literals in others. We aren't consistent in checking limits. This PR makes the use of the constants in Cell/AddressRange the "official" source, deprecates all other constants, and substitutes the constants wherever literals are used. A number of different edge case tests are added.
During testing, I discovered that `columnIndexFromString` correctly throws an exception for 4-character string, but allows `XFE` through `ZZZ`, all of which are also invalid. There are similar inconsistencies with related routines, and this PR attempts to make them operate consistently. One suprise is that throwing for `row=0` causes serious regression problems, so it continues to be permitted (but the high row limit is enforced).
Further, Reference Helper sometimes dips into negative numbers, resulting in totally unexpected results (-1 affects column Z, -2 column Y, etc.). It is changed to ignore rows and columns outside the limits.
Fix#3687. Worksheet methods insertNewRowBefore and insertNewColumnBefore call ReferenceHelper insertNewBefore. That function fills in "missing" cells with null values. However, for boundaries, it uses getHighestRow and getHighestColumn. It should be sufficient to use getHighestDataRow and getHighestDataColumn. When there is a big gap between getHighest... and getHighestData..., this can result in a big increase in memory usage, and in file space when saving the spreadsheet. New test InsertTest demonstrates the problem by populating a worksheet with cells A1:D5 (so highestDataRow is 5), but also setting row 1000 to invisible (so highestRow is 1000).
The major part of the change is in ReferenceHelper::insertNewBefore, which will now use getHighestData... for its boundaries when filling in the missing cells. Changes of less impact are made to duplicateStylesByColumn and duplicateStylesByRow so that cells which don't yet exist are not created unless the style that will be applied is not the workbook default style.
As for reducing the file size, Writer/Xlsx/Worksheet is changed so that cells whose value is null or null-string and which use the workbook default style are not written to the output spreadsheet. This requires some changes to existing test ReadBlankCellsTest; I don't think the difference should matter to the end-user.