[Feature] Navigation Guards

[BurkusCat]

Is your feature request related to a problem? Please describe.
If I have unsaved changes on a page, I want to prevent the user from leaving it unless they confirm in a dialog they want to discard the changes. If a navigation initiates to an authenticated part of the app, I want to prevent the user from being allowed to navigate to that page unless they are first logged in.

Describe the solution you'd like
Something like Angular's route guards
https://angular.io/api/router/CanActivate
https://angular.io/api/router/CanDeactivate

Describe alternatives you've considered
N/A

Proposed APIs
If possible, try to propose how the API might look. For example:

Task<bool> CanNavigateFrom()
Task<bool> CanNavigateTo()

Additional context
N/A