DASH: Implement Manifest-chaining

[peaBerberian]

NOTE: To facilitate tests, I deployed that work on the https://developers.canal-plus.com/rx-player/mpd-chaining demo page

This is a very naive implementation of the DASH Manifest chaining concept which allows to signal a next content to load from the first content's MPD. Use cases we've heard of are mainly pre-roll or post-roll contents (basically ad before and after a content) including for live contents.

I only handle the chaining at the end of the previous content for now. There is a second situation "Fallback Chaining" which is supposed to do so at the "failure" of a content that I do not yet handle as it poses much more questions in terms of RxPlayer API.

Even in that very simple chaining after ENDED, there is still some API question left: should we send an event when chaining? What loadVideo options should we set, should we ask the application? How can an application configure the start time of one of the chained content?

To note also that some other players preload the future content at the end of the previous one with the goal of having a lower transition time, I saw mainly the shaka-player with this. The RxPlayer has no preload concept yet.

[github-actions]

✅ Automated performance checks have passed on commit 216c111e2026390360ee01a5f65121973a66990d with the base branch dev.

Details

Performance tests 1st run output

No significative change in performance for tests:

Name	Mean	Median
loading	24.55ms -> 24.88ms (-0.327ms, z: 0.41297)	34.95ms -> 34.95ms
seeking	422.24ms -> 426.92ms (-4.679ms, z: 0.55685)	1518.30ms -> 1516.35ms
audio-track-reload	31.53ms -> 31.54ms (-0.002ms, z: 0.43421)	47.10ms -> 47.10ms
cold loading multithread	50.48ms -> 49.90ms (0.578ms, z: 10.19429)	74.55ms -> 73.65ms
seeking multithread	56.02ms -> 45.31ms (10.704ms, z: 0.46676)	19.55ms -> 19.50ms
audio-track-reload multithread	30.10ms -> 29.92ms (0.182ms, z: 1.98375)	43.95ms -> 43.95ms
hot loading multithread	19.88ms -> 19.67ms (0.217ms, z: 4.00063)	28.95ms -> 28.80ms