Remove Caption File References from HLS Manifest

[joncameron]

Description

See #5695 for details on why captions are being removed from the HLS manifest. In short, having captions in the HLS manifest and also delivered via IIIF manifest means ambiguity and difficulty in the media player environment across browsers.

Currently, captions are in the manifest for an item like this in the HLS manifest:
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",LANGUAGE="en",NAME="English",AUTOSELECT=YES,URI="/master_files/0p096d77r/caption_manifest"
This can be removed.

Done Looks Like

• Caption references do not appear in Avalon's HLS manifests
• Re-test to ensure that captions do display on iOS devices in the native player
• Ensure that HLS player is using the IIIF manifest, rather than HLS captions

[masaball]

I was unable to test with my local system because I could not get Browserstack iOS to work with localhost. From testing on desktop, the current Ramp build in Dev is removing the non-HLS captions from the track listing so when the player instantiates, the captions button is present for a split second and then disappears. I think this is because we have not brought in a build containing samvera-labs/ramp#428 yet. Once that is brought in, captions should display as expected. I did test manifests from Avalon on the Ramp demo site and everything looked good.

Captions in the embedded player were working as expected for desktop, but I could not test on iOS for the same localhost issues already mentioned.

[elynema]

Once the Ramp build with #428 is brought in, this can be tested on avalon-dev. Ramp PR #443 is complementary work to remove Ramp code that handles duplicate captions.