Add more conformance clips to FATE to enhance code coverage.

[nuomi2021]

From James:

There's not a lot of VVC bitstreams currently in the FATE suite, so if you know of any that will increase the coverage (See for example http://coverage.ffmpeg.org/index.vvc_intra.c.5d0b519a39871515a1754ee8847b6d69.html#l678, where vvc_predict_ibc() is never run), then please make a test for it and I'll upload the sample.

https://ffmpeg.org/pipermail/ffmpeg-devel/2024-April/324956.html

the target is to get 95%+ coverage for vvc code. all major branches are covered.

[nuomi2021]

@frankplow , are you interested in this? It's a good task to familiarize the code.