ReadOnly ContentArea and ContentReferenceList links not working

Description

If ContentArea or ContentReferenceList is read-only, it's not possible to navigate to children.

For example, if property is not Culture Specific and a user is viewing content in a language branch, the Editor has to change the editing context to the master language.

Steps to reproduce:
1. Add ContentArea and ContentReferenceList read-only properties to model

 [Display(GroupName = SystemTabNames.Content, Order = 340)]
[Editable(false)]
public virtual IList<ContentReference> ContentReferences { get; set; }
 
[Display(GroupName = SystemTabNames.Content, Order = 340)]
public virtual IList<ContentReference> ContentReferences2 { get; set; }

2. Override SetDefaultValues method and assign deafult values:

public override void SetDefaultValues(ContentType contentType)
{
    base.SetDefaultValues(contentType);
 
    this.ContentReferences = new[] {ContentReference.StartPage, new ContentReference(7) /* Alloy Track */};
    var relatedContentArea = new ContentArea();
    relatedContentArea.Items.Add(new ContentAreaItem { ContentLink = ContentReference.StartPage });
    relatedContentArea.Items.Add(new ContentAreaItem { ContentLink = new ContentReference(9) /* Alloy Meet */ });
    this.RelatedContentArea = relatedContentArea;
}

3. Run the site and add a new page.

Expected: It is possible to navigate to ContentArea/ContentReferenceList children.

Actual: The Readonly property doesn't support navigation.