Wpf.HwndHost Example - Demo Multiple tabs

The `WPF` example has multiple tabs, the `HwndHost.Example` is very basic at the moment.

There are a few ways we could do this.

- Copy paste the code from the `WPF` example
- Update the `WPF` example to support demoing both `HwndHost` and `WPF`
- Have the `HwndHost` example reference the `WPF` example and reuse compoents and `ViewModels`, just implementing a different view

Open to other suggestions.

Start by comparing the existing WPF example with the basic HwndHost.Example. Review the three reuse approaches listed in the issue and determine the intended structure before changing anything. Done means the HwndHost example demonstrates multiple tabs without duplicating more code than necessary.

Written by the indexing model from the issue text.