WIP Removing Rows or Columns that Include Edge Ranges

[oleibman]

This PR will probably remain in draft status for some time. It needs updates, and I need more time to understand exactly what it is doing. It is a replacement for PR #2096, intended as a fix for issue #1449. That PR has been stuck, with a good deal of acrimony, for over 2 years. In the interim, all the parameters for the functions involved were renamed, the functions were refactored to have fewer parameters with new class properties replacing the missing parameters, special code was added for absolute references, and code was refactored putting some of the methods involved in a new class under a new method name. In addition, the original PR was not Php8-compliant (one of the sticking points regarding implementing it), and there were a great many formatting problems (another sticking point). This has made it very difficult to figure out exactly what was intended in the original PR.

This PR (a) addresses some of the issues associated with the original issue (deleting columns/rows at the end of a range passed to a formula on the same sheet), and (b) does not cause any existing tests to fail. Many more unit tests are needed (another sticking point); in particular, there are changes involving data validations, comments, defined names, and other elements which are not adequately tested.

Aside from those, PhpSpreadsheet does not adjust formulas on a different sheet which involve deleted rows/columns, and it should, as Excel does.

Similarly, it appears that Excel doesn't do anything extraordinary when the right/bottom part of the range is deleted, but when the left/top part is deleted, it converts the range to #REF! at least some of the time. This needs more research; if confirmed, it needs to be added to PhpSpreadsheet.

This is:

• a bugfix
• a new feature
• refactoring
• additional unit tests

Checklist:

• Changes are covered by unit tests
  • Changes are covered by existing unit tests
  • New unit tests have been added
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change and a link to the pull request if applicable
• Documentation is updated as necessary

Why this change is needed?

Provide an explanation of why this change is needed, with links to any Issues (if appropriate).
If this is a bugfix or a new feature, and there are no existing Issues, then please also create an issue that will make it easier to track progress with this PR.