Separate CEA captions into different groups based on language

[adadukin-dolby]

Problem: CEA-608 and CEA-708 captions end up in the same group for DASH.
Proposal: split all text captions into different TrackGroups, similar to HlsMediaPeriod implementation

More context available at: #3113

[tonihei]

Thanks for the fix - unfortunately the PR is based on the release branch, so I can't merge it as it is. Could you open a new one based on the main branch? Also happy to simply apply the same changes internally if you prefer.

(Second note: the branch is not accessible and will results in an 'evil' merge. Previous PRs from Dolby had the same problem and I was told that's no issue, so I assume the same is true here).

[adadukin-dolby]

Thanks for the fix - unfortunately the PR is based on the release branch, so I can't merge it as it is. Could you open a new one based on the main branch? Also happy to simply apply the same changes internally if you prefer.

(Second note: the branch is not accessible and will results in an 'evil' merge. Previous PRs from Dolby had the same problem and I was told that's no issue, so I assume the same is true here).

Hey @tonihei,
Pointed the branch to main