Replace rights objects instead of deleting and adding new objects

When some rule are persisted using the current API, we should try to recycle objects that currently exists in the page, in order to prevent uncontrolled grown of objects number. Also, this will also impact the difference between 2 versions. From this point of view, the situation is as follows:

• current behavior: the user see the deletion of all (rights) objects from the page & each new rule is seen as a new object (1 object/rule to be persisted)
• desired behavior: the user see the changing of some properties for the objects that are already present in the page. If the page has a number of rights objects lower than the number of the objects that needs to be persisted, we should move the properties of objects that needs to be persisted into the objects that already exists in the page and after that, adding new objects to the page. Otherwise, we will use the objects that are already persisted with updated values (from rights that needs to be persisted) and delete unnecessary ones.