Adapt Unauthorized Page to Display Custom Messages for app_application Users

### Background Information

The platform currently has an Unauthorized page that provides feedback to users attempting to access restricted pages without the required role. However, this page does not currently handle cases specific to app_application users. We need to adapt the Unauthorized page so it can display a customized message for these cases, providing more targeted guidance and enhancing the user experience.

### Steps to Reproduce

1 - Log in as an app_application user without the role required to access a restricted page.
2 - Attempt to navigate to a page that requires authorization.

### How

Update the Unauthorized page to support a custom message for app_application users. This involves modifying the existing Unauthorized page logic to detect when the user falls under the app_application context and display a specific message tailored to these users.

### Expected Behavior

When an app_application user without the required role attempts to access a restricted page, the Unauthorized page should display a custom message relevant to app_application, clearly indicating why access is denied and what steps, if any, the user can take.