There is no UI to see or set extension rights on a page only - regression for Like right

This concerns the extension rights introduced by XWIKI-17533 .

How to reproduce (screenshots in french):

• go to a page administration
• for platform rights there are 2 sections:
  • rights: page and children
  • rights: page
    
• none of these 2 sections displays the like right - see also XWIKI-18823
• for extension rights there is a single section, "permissions des extensions", which shows the like right
• it's not clear to what this section applies but it appears to apply to page & children (by testing)
  

Expected result:

• as for regular rights, there should be a way to set the extension rights for the page only

Actual result:

• no way to see or set the rights of extensions on the page only, from the UI