Inconsistent reading mode when getting pages and files

[michalkleiner]

It seems like Page items are collected from draft stage whereas File objects have no affordance for this (probably from times before SS4 where files weren't versioned). This may lead to incorrect numbers being reported when there are unpublished files.

https://github.com/silverstripe/silverstripe-sitewidecontent-report/blob/3/src/SitewideContentReport.php#L86-L87