Fix Permissions Across Copied Pages

Fix permissions carrying accross copied pages.

`Page::getPermissionObjectIdentifier()` tries to call
`Page::getPermissionCollectionID()` but this is set to the original
page upon `Page::duplicate()`

- if set to `OVERRIDE` update Pages table with proper inheritance cID
Merge pull request #1238 from mkly/fix_page_copy_permissions

 Fix Permissions Across Copied Pages