Slider: Accessibility - Testcases: Fixing CodeStyle issues

Testcases for changes to support accessibility

Ticket: #4739
Slider: Accessibility: Reverting changes on external code

According to the feedback of tjvantoll, I reverted the code-style correcting changes on former existing code

Ticket: #4739
Slider: Accessibility: Code optimization

According to the feedback of tjvantoll, I optimized the used code

Ticket: #4739