[Bug] [Demo App V4] Updating Scenario Page Content

[Dave3130]

This pull request makes small adjustments to the Scenarios page UI, mainly to improve clarity and update placeholder content.

UI and Content Updates:

• Renamed the customer reference input field and its associated id from static-id-field to fixed-id-field for consistency.
• Changed the toast notification title from "Demo notification" to "Toast Notification" for better context.
• Updated the example share link from https://demo-app.local/scenario to https://abc.com to use a more generic placeholder.