Article : allow filter docs associated to article-tag

We can associate any doc type to an article. The article shows the lists of associated docs.
But we can't use the filter engine to have the list, and add other filter criteria.
It would be useful to use the "Multi-criteria search" field to add a criteria on associated article.
On API side, we must just add a criteria "c", with same syntax as "r" or "w" (c=\ : c=1234,5678,7654)
Today, on an article page, the list of associated docs (WP, routes, outings, ...) are not limited to 30-40 items : all items are displayed.
The new criteria allows to limit the number of docs displayed on the article page, and a button would have a link to the full list (as for outing list on a route page). This button already exists for outing list, with the "c" criteria in the link (but the criteria doesn't work).