< character in a string property is displayed as XML entity

How to reproduce:

• create simple application with the following:
  • a string property
  • the sheet of this application should not use the

    {{html wiki=true}}

    macro like the standard app within minutes does, but only display the fields from a velocity script

• add an entry of this application
• in the string property field, type 23 < 45
  
• save

Expected result:

• when saved, 23 < 45 displays on the screen
  

Actual result:

• 23 < 45

  is displayed on the screen
  

This particular usecase (involving < ) is caused by the fix for XWIKI-17374 - so it would be a regression - but the issue should also be there for other situations of property values / displayers with some special XML characters (any displayer generating only HTML entities without actually generating tags would also have failed to be seen as HTML by the displayer and so rendered as is).