Issue #3197068: Modernize conversion process on install

• Uses the entity update API to add the revision fields
• Uses a batch to make the user entities revisionable
• Normalizes revision fields instead of copying legacy node ones (vid => revision_id etc.)
• Changes settings: allow to disable revisions (no new revision) and disable password revisions
• Cleans up code (errors, coding standards etc.)
• Adds Drupal 9/10 compatibility
• Adds post update hook implementations to allow upgrading from previous 8.x version of this module

Closes #3197068