Page navigation from search should expand TreeView and select page

[michael-hawker]

Describe the bug
When you search for a page like ItemsRepeater in the sample app you're taken directly to the page, but you have no idea where that page exists in the navigation tree. It would help with the discovery of similar controls if they page is brought forth as the selected/opened page in the NavigationView.

Steps to reproduce the bug

1. Go to Sample App
2. Search for a control in the search box
3. Select a choice to navigate to that page from the dropdown

Expected behavior
Page selected in NavigationView.

Actual behavior
No indication of which page I'm viewing in hierarchy.

Screenshots

Version Info

Gallery version (found on Settings page):
1.2.15.0

Windows 10 version:

• Insider Build (19624)
• November 2019 Update (18363)
• May 2019 Update (18362)
• October 2018 Update (17763)
• April 2018 Update (17134)
• Fall Creators Update (16299)
• Creators Update (15063)
• Anniversary Update (14393)

Device form factor:

• Desktop
• Mobile
• Xbox
• Surface Hub
• IoT

Additional context

[gregwoo-microsoft]

@chingucoding do you know if your solution (PR #478) can be applied to the two issues mentioned above?

[marcelwgn]

#613 is partially fixed (the selection indicator is missing), #726 is not fixed.