[SPO] Unpublished pages appear in search results

[dennis-tismenko]

Bug Description

With DLS enabled, unpublished Sharepoint Online pages are still returned in search queries to all users that have permissions to view the page.

Unpublished pages are ingested and added to the ES index as they are still considered accessible to both owners and editors of the document. However, the Sharepoint Online API doesn't appear to be updating their ACLs for that page when it goes into an unpublished state, so our SPO connector will continue to treat these pages as accessible to anyone with view permissions.

Also, we should consider exposing a field representing the published state of a page (if the Sharepoint API allows for it).

To Reproduce

Steps to reproduce the behavior:

1. Add a page to a site in Sharepoint Online and publish it.
2. Within Sharepoint Online, navigate to "Manage access" for the created page and add some users/groups with "View access"
3. Sync content with DLS. Verify that the site_page created was ingested and _allow_access_control contains the users with view access.
4. Unpublish the page in Sharepoint Online.
5. Perform a full content sync.
6. Document is still indexed (expected) and _allow_access_control is unchanged (bug).

Expected behavior

The _allow_access_control field should only contain owners and editors of the page, implying that users performing searches on the index without ownership/edit access of the unpublished page will not see it in their search results