Expose a style property for the PdfViewerNavigateToPageToolbarItem to enable easy customization of its appearance, the RadEntry and Label.

When using a screen reader on Android, iOS, WinUI, the reader do not reach the pdf document. Provide option for screen reader support.

When using the back button of the NavigationButtonToolbarItem it does not work, so I cannot navigate back.

The behavior also happens in the PdfViewerSearchNavigationToolbarItem 

When loading a pdf from a file, uri, etc, except as an embedded resource and Switching the app to background and then to foreground again forces an app restart. This is due to the fact that the stream closes.