Subtitle settings - Show example text to present selected choices

**Is your feature request related to a usage problem (not a bug)? Please describe.**
When user is changing the look of their subtitles they can't see how they look if there are no subtitles presented on the video at the exact moment of clicking the subtitle settings.

**Describe the solution you'd like to see implemented**
Please show example text, e.g. 'Subtitles example' in the place where subtitles are presented (if normal subtitles are present they should be hidden).

**Describe alternatives you've considered**
I don't think there are other alternatives.

**Screenshots**
Example from Youtube

**Additional context**
No additional context.