feat: Add Safari Technology Preview, iOS and iPadOS with simulators

[tykus160]

Works OK with Technology Preview and simulators. Wasn't able to check on actual devices.

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[joeyparrish]

This is great, thanks! I'll try it out in our lab before merging, but it looks good to me.

[joeyparrish]

I was able to test Safari TP, but on iOS it failed initially because it tried to connect to localhost. After modifying shaka-player's karma.conf.js to set the hostname field to the mac's IP, that worked. However, we then have shaka-player test failures on iOS related to MediaSource (which isn't available on the platform and is unconditionally referenced in the tests).

So there is some follow-on work necessary in Shaka Player, but this PR is definitely working. Thank you for this!