More Sophisticated Workbook Password Algorithms (Xlsx only)

[oleibman]

Fix #4673. Our password hasher can handle different algorithms, but the workbook password (for maintaining the structure of the workbook, not for encrypting the entire workbook) currently supports only the single algorithm that was in place many years ago. Expand it, and Xlsx Reader and Writer, to be able to use, say, SHA-512, which is what Excel itself uses.

The revisions password needs to be expanded in the same way as the workbook password. It is used for file sharing, but MS has deprecated it because it feels that modern technologies introduce better ways to accomplish what it was needed for. You'll need to look pretty hard to even find it in Excel - it's not, for example, on any of the ribbons. Nevertheless, the solution here is pretty much identical to the solution for the workbook password, so I am fixing it at the same time.

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.