CMS-3464 Make property name on PageComponent-s optional
PageComponent name is now optional
ComponentPath does no longer contain name of PageComponent, only it's index in it's Region.
PageComponent-s holds now reference to parent Region and Region-s to parent LayoutComponent (if any). ComponentPath and RegionPath are now dynamically resolved upon request (using parent). This should make make less room for errors related to path (since it will always reflect current graph of objects).