Access nt:targetDocumentsIds in Page Providers

Since LTS2017,

property nt:targetDocumentId is not anymore set with the target document's UUID, and property nt:targetDocumentsIds has to be used instead.

(cf https://jira.nuxeo.com/browse/NXP-21025?focusedCommentId=339780&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-339780 )

However, when configuring a Page Provider, the Binding

task:targetDocumentId 

is proposed and

task:targetDocumentsIds 

is not proposed.

For releases LTS 2017 onward in the Page Providers tab, Studio should propose to access

task:targetDocumentsIds 

Expected result; a working page provider for Task ecm:mixinType.