page_detail: content object changes are not handled correctly

[Jürg Messmer]

Occurs: since jQuery 3 update and rework of page_detail (menu) default page type

1. Adding a new content object to a (filled modules) container is not "registered" properly.
   The inherit content message should be removed (if inherit is true and no object exists) as soon as a content is added (adminAddObjectToContainer)
2. Moving the new content object directly after adding does not save the new location. If page is being reloade, the object is still at the original location.

[Jürg Messmer]

Sorry, wrong issue declared as duplicate

[Jürg Messmer]

Fixed with 30af872