Resets the actual fields instead of AddPageArea properties
Before this commit, BookPage would reset every property inside AddPageArea resulting in breaking the bindings of these properties and in them having default values. So, we end up with a new page area object but with its default values submitted to our model. This commit fixes the mentioned issue by actually resetting the inner fields of the components of AddPageArea so we don't break the originally created bindings
Edited by Mahmoud Khalil