Setup/ Improve test app

[Alex-Witkowski]

Is your feature request related to a problem? Please describe.
The test app should use the Matomo SDK and showcase the initialisation of the SDK, the tracking of pages and events.

Describe the solution you'd like
Initialisation:

• In App code it should be clear how the SDK is set up. So developers should be able to transfer this code to their own project.

Page tracking

• The test app should have multiple pages and a navigation between them should showcase how the Matomo page tracking is working.

Event tracking

• The test app should have several buttons for different events and categories to showcase the tracking ov events with Matomo.
  Describe alternatives you've considered
  A clear and concise description of any alternative solutions or features you've considered.