DBTreeLists don't work in sheets created with AppWithinMinutes (and not only)

How to reproduce:

• make an application within minutes with a dbtree list property
• edit the class in class editor mode to put a proper hql query to the dbtree list (can use http://extensions.xwiki.org/xwiki/bin/view/Extension/Classification+Application to make a hierarchy)
• if the version on which you're testing is affected by XWIKI-8760 , patch that one first to have proper results

In the application created as such, the dbtreelist property will not display properly in edit mode, it will not be styled properly and there will be no checkboxes displayed to select entries from the tree.

See http://jira.xwiki.org/secure/attachment/29433/brokenDBListTreeColibri.png and http://jira.xwiki.org/secure/attachment/29432/brokenDBListTreeFlamingo.png .

Note that the issue could reproduce in other cases but particularly reproduces for applications created with AppWithinMinutes (see reason in the comments).

This issue was discovered during the investigation for XWIKI-11382 , see comments of that issue as well.