Fixes #153093

This PR implements a solution to dynamically manage TapRegion when navigating between pages in the app. By using a custom TapRegionNavigatorObserver, TapRegion instances are automatically registered and unregistered during push and pop route events. This ensures that onTapOutside callbacks are triggered only for the active regions on the current page, preventing false positives and improving the consistency of touch region behavior across the app.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• I followed the breaking change policy and added Data Driven Fixes where supported.
• All existing and new tests are passing.

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