descriptor type updates v5.0.0

[stschr]

#4205

This PR addresses:

• settings structure is kept as close as possible with previous version; if used as with v4.x, default schemeIdUri are assumed
• no changes to selection logic except that schemeIdUri are compared as well
• deprecates old elements and uses descriptorType elements only
• updated/cleaned unit test

Let's discuss some details in next week's call (2023-08-10).

[stschr]

Another observation:
I just figured out that sample "Multiple Language Timed Text Sample" ist no longer working - due to a wrong schemeIdUri in the MPD (it uses <Role schemeIdUri="urn:mpeg:dash:role" value="subtitle" /> - note the missing year :2011 at the end of the schemeIdUri - interesting: this is not detected by the conformance validator).

I could either:

• update the sample to explicitly set the invalid schemeIdUri
• keep the sample "as is" (which would require to update the MPD)

[dsilhavy]

Another observation: I just figured out that sample "Multiple Language Timed Text Sample" ist no longer working - due to a wrong schemeIdUri in the MPD (it uses <Role schemeIdUri="urn:mpeg:dash:role" value="subtitle" /> - note the missing year :2011 at the end of the schemeIdUri - interesting: this is not detected by the conformance validator).

I could either:

• update the sample to explicitly set the invalid schemeIdUri
• keep the sample "as is" (which would require to update the MPD)

Thanks, for means of completion this is the wrong MPD: https://dash.akamaized.net/dash264/TestCases/4b/qualcomm/1/ED_OnDemand_5SecSeg_Subtitles.mpd . We should fix the MPD. The default sample MPD https://livesim.dashif.org/dash/vod/testpic_2s/multi_subs.mpd should still work.