test: 🧪 implement E2E tests on our templates

[karlbaumhauer]

Description

@mariohamann pls fill in some information about testing our templates (as discussed in our call - has been approved by the rest of the team).

Technical Information

DoR

• Item has business value
• Item has been estimated by the team
• Item is clear and well-defined
• Item dependencies have been identified

DoD

• Documentation has been created/updated (if applicable)
• Migration Guide has been created/updated (if applicable)
• Relevant E2E tests (Features, A11y, Bug fixes) are created/updated
• Relevant stories (Features, A11y) are created/updated
• Implementation works successfully on feature branch