Fix element binding suggesting name attribute on first element selection

Steps to reproduce:

• In Drawer > Drawer Items, create a new Page.
• On the element binding section select any element (ex: <nuxeo-actions-menu>). Notice that there will be a name attribute, even if the selected element doesn't have a name attribute.
• Unselect the element.
• Select the same element that was previously selected. Notice that the list of attributes is inconsistent with the previous one and the name attribute is no longer there (if the element does not declare a name attribute).

This will happen in other types of contribs, not only for Drawer Items. It will also happen for any element that is selected.

This might be related to the way some features are initialized, considering that some of them contain a name attribute from the start.

Initially we thought that this issue could have been caused by the fix of NXS-6292 but upon further investigation we could conclude that it was not the case.