API Author is too generic for a reserved name

[muskie9]

API Author is too generic for a reserved name

In an upgrade from a CMS3 site to CMS4 a custom model extending Page with Author as a field no longer rendered the value of that field.

Currently Documented Workarounds
In silverstripe/cwp#209 a workaround was noted as creating a new method to return the expected value. This is possible, but should not be required as the term Author is a very generic term and likely should not be inherently reserved.

Possible Solutions
Updating AuthorID in $db_for_versions_table config to a Versioned specific naming convention would make the current implementation less generic. This would then require a change to the naming convention of Versioned::Author() to reflect the change.

As a part of upgrading (assuming to a new major version), a basic task running a wholistic DB::query() call to move the data, then clear the existing column could be an option. This would need a bit more thought to ensure there are no negative consequences to the data move as it relates to supported modules and ensuring that data is preserved.

Acceptance criteria

• Rename Author/AuthorID in Versioned to something less generic (e.g. VersionAuthor)
• Provide migration task to ensure data integrity when upgrading to new major version that includes this change
• The changelog makes it very clear what is needed to upgrade
• Perhaps there should be some fallback or clear error message for people who don't read the changelog?