Add an ISM Parser

[WalkerTheWolfXXII]

Is your feature request related to a problem? Please describe.
Services such as AMZN use ISM for video tracks with Dolby Vision.

Describe the solution you'd like
Implement an ISM parser, similar to DASH and HLS parsers.

Describe alternatives you've considered
N/A

Additional context
N/A

[Azki89]

Dupe of #4
Also, from my experience, it's not that easy. Shaka can't decrypt files from MSS manifest, so need to implement mp4decrypt support, there are some problems with AAC audio (afaik), usually/always no information about FPS (it should be in the CodecPrivateData but it's not), no information about HDR. You should be able to get some/all the missing data from the init file, but still, it needs a lot of things to do.