Add support for multi-period/stitched DASH manifests

[rlaphoenix]

Is your feature request related to a problem? Please describe. Currently, Devine is assuming the first Period for listing tracks and downloading tracks. Most DASH playlists are just a single Period therefore selecting the first would be fine, but some DASH playlists aren't. Some start the playlist with a Period which would be an Ad break, and some split up the content e.g., 10-minute splits with ads in between. So even if the first Period is not an Ad, it's likely not the full content unless it's a single Period manifest (or two-period manifest with one of them being the full content).

Describe the solution you'd like The only fix here would be to somehow match Representations across Periods to be the same stream, resolution, language, and bitrate (and so on). Then compile a list of representations and download them in order, which may not be the order as-written in the manifest, but based on duration and offset.

Describe alternatives you've considered The only other alternative right now would be to filter out Period's you don't want, then hope one Period (the selected period) is the full content. Or, try to find an endpoint that gives you the full content as a single non-segmented DASH manifest. E.g., non-stitched.

Additional context N/A