Update Permission Error to be a toast message with styling

[maxmurphySF]

What

This task involves updating the display of permission errors in Backstage. Instead of showing plain text on the page, the error message will be transformed into a styled toast notification. This change aims to improve the user experience by providing a more visually appealing and less intrusive way of communicating permission-related issues to the user.

Done When

• A new toast component has been implemented or an existing toast library has been integrated into the application.
• The permission error message is now displayed as a toast notification instead of plain text on the page.
• The toast message has been styled according to the application's design guidelines, ensuring consistency with the overall UI.
• The toast includes appropriate visual cues (e.g., an icon) to quickly indicate that it's an error message.