Split documentViewPage contribution based on different behaviors

At the moment, the documentViewPage contribution for WEB-UI (in nuxeo-web-ui-bundle.html) contains two different behaviors: one using the nuxeo-collapsible-document-page for folderish/non-collection documents, and other using the nuxeo-document-page for regular documents.

We should split this contribution in two to keep consistency and api between web-ui and Designer.