Add the possibility to ignore pinned pages when sorting document tree macro results

The possibility to sort document tree pages using different fields (name, title, date , creationDate) and different orders (esc, desc) has been recently implemented, see XWIKI-21155. And as it is implemented now this feature takes in consideration the pinned pages when ordering the macro results, so, it could be a good improvement if we have an option to force ignore pinned pages and manual order already applied on a given document tree.

Here is an illustrative example of the need.

• On an XWiki instance create a page named "Test" with 5 sub pages "Test 1", "Test 2", "Test 3", "Test 4", and "Test 5"
• By default these pages are ordered by their title in ascending order, see screenshot :
• 
• Administer the "Test" page and add the "Page 3" to the pinned pages, now the "Page 3" is displayed first in the document tree, see screenshot
• 
• Now, on another page use the documentTree macro to display the "Test" page tree sorted by title in descending order.

{{documentTree root="document:Test.WebHome" sortDocumentsBy="title:desc"/}} 

• You can see that the order of the page changed but the "Page 3" is still displayed first, see screenshot
• 

Currently there is no possibility to display the pages in their real title ascending order ("Page 1", "Page 2", "Page 3", "Page 4", "Page 5"), so, we need a parameter in the documentTree macro that allows ignoring pinned pages and manual order when sorting the pages.