[Task](exampleapp): Rework the example app according to the new design guidelines

[edda]

Task Description
Rework the existing example app, ensuring it follows the guidelines outlined in the design document. This will serve as a real-world test of how easily developers can adopt and implement the design system.

Sub-tasks

• Fix exisiting exampleapp content following the guidelines
• Expand app with additional components or pages where necessary (to use as many of our standard patterns/components as is feasible). Get in touch with @franzheidl with questions regarding this point.
• Collect feedback to design guidelines, particularly where things are hard to understand, information that needs to be highlighted so its harder to miss, etc.

Additional Context
The idea is to try to improve the example app following the guidelines so that it can act as a reference implementation of said guidelines. The additional goal of this task is to get feedback on this first version of the guidelines document to be able to improve it.