Inconsistent way of presenting XClass name in object editor

In object editor the XClass selector to create a new xobject is using the actual title of the page where the XClass is defined, while when displaying the XObjects we're using the reference of the xclass.
In some cases, it can be difficult to make the link between the title and the reference.

Reproduction steps:

• Create a new page and open the object editor
• Add a new "XWiki Sheet Include" object

Expected result:

• An xobject "XWiki Sheet Include" is created

Obtained result:

• An xobject "XWiki.DocumentSheetBinding" is created

Note that I don't know if we should actually only use the reference of the xclass in the select, or if we should only use the title of the page where the xclass is defined to list the xobjects.