Add support for ID3 tags in mp4

[ismena]

We use mux.js to parse ID3 tags in ts streams.
Mp4 also supports embedding ID3.
We should see if we can use mux.js to parse those or implement the parsing using our mp4 parser.

[avelad]

Please consider not using mux.js, because this adds an external dependency that might not be desired.

[avelad]

@joeyparrish already done with ID3 parsing in the Shaka.

[joeyparrish]

Fixed in PR #4409.