Fixed RTL languages punctuation mark issue

[orenskl]

Changes
Add the unicode LTRM character for subtitles

Issues
Fixed #4296

[nielsvanvelzen]

While I'm sure this fixes the LTR issues, I'm not sure if this is a proper fix for the underlying issue. Modifying each line to force unicode directional marks into them seems like a hack we should not need to do, and it may even introduce side-effects.

[orenskl]

I agree this is a hack/patch for this issue, while I did tested this with both LTR and RTL subtitles and it seems ok.
Subtitle direction should be handled correctly in the SubtitleView but I think there is a bug or an issue in the media3 library so I guess we will have to wait for it to be fixed.