Unit Testing and E2E Testing for Header Component

[HabakukBeneke]

Description

Currently, unit testing and E2E testing for the components have not been implemented. The header component is completed, and testing needs to be added. Starting with unit tests and E2E tests now will ensure that the coverage reaches the target of 90% in the future, as the app grows. This will prevent difficulties in achieving full coverage later.

• Expected Behavior: All functionalities of the header component should be covered by unit tests and E2E tests, ensuring stable and reliable behavior.
• Actual Behavior: No tests are currently implemented for the header component.
• Steps to Reproduce: N/A

[HabakukBeneke]

This issue still not completed