fix(plugin-meetings): small refactor of code handling Locus API responses

[marcin-bazyl]

COMPLETES #SPARK-697765

This pull request addresses

Code is not always going through the same functions when handling Locus API responses

by making the following changes

This is part of the webinar 5k work. It is a bit of refactoring that's needed for the rest of the webinar 5k work.

Changes done:

• MeetingUtil.remoteUpdateAudioVideo() used to return just the locus from the response and MuteState class was calling LocusInfo.handleLocusDelta() with that Locus, now instead MeetingUtil.remoteUpdateAudioVideo() returns the full response and the whole response is passed to MeetingUtil.updateLocusFromApiResponse() which calls LocusInfo.handleLocusAPIResponse() which calls LocusInfo.handleLocusDelta() - so the end result is the same but the code goes through MeetingUtil.updateLocusFromApiResponse(), which is the one function that all API responses (apart from Join which is special) should go through
• in MeetingUtil renamed updateLocusWithDelta() to updateLocusFromApiResponse() - to make it clear that this it the function that should always be used for handling any Locus API response

This refactor is needed for webinar 5k work, because when we use Locus hash trees, the API responses contain a body that doesn't have the locus field but instead contains datasets and a set of hash tree objects, so it's important that all code handling any API responses from Locus goes always through the same util functions and that the whole response (not just the locus part) reaches LocusInfo class.

Change Type

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Tooling change
• Internal code refactor

The following scenarios where tested

unit tests, end-2-end manual testing as part of webinar 5k work with all the other changes in draft PR#4427

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