Adding buttons to the title bar

[LeoKhariton]

Description

I would like to be able to control the addition of the back button on the navigation bar in the title bar.

maybe there is already some way to do this, please point it out to me

Public API Changes

<FlyoutItem HasBackButton="True"/>

Intended Use-Case

I'm using a shell and I want to switch from a regular content page to a tabbed page, but I can't add a back button to it