[Fix] `Search for web map` navigation bugs

[CalebRas]

Description

This PR fixes a regression where opening the Search for web map sample would just show "No Sample Selected" on iPhone (iOS 17). This was caused by the navigation stack added in #477. Those changes were reverted, and the stack was moved to the NavigationSplitView detail. This solution should work for samples that use a navigation link in the future.

Linked Issue(s)

• swift/issues/5798

How To Test

Test the Search for web map and Augment reality to show hidden infrastructure samples:

• On iPhone, ensure the samples launch as expected.
• On iPad, ensure the samples have a navigation back button after clicking the navigation link in landscape mode.

Screenshots

Before	After

[CalebRas]

Removing Mark since he is out for the next couple days.