Refactor/youtube api client

[xakep8]

Description

Created YoutubeApiClient and moved the broadcast and stream related functions from YoutubeApiWrappers to YoutubeApiClient and added apiClient object to YoutubeApiWrappers. This helps move the mixed ownership issue from YoutubeApiWrappers inheriting from YoutubeAuth only because it needs OAuth information, follow up refactor would be to move the broadcast setup/start/stop out to YoutubeBroadcastController and create a YoutubeService class which owns the OAuthTokenStore, YoutubeApiClient, YoutubeBroadcastController and the YoutubeDockController.

Motivation and Context

#13482 (comment)

How Has This Been Tested?

xcodebuild -configuration RelWithDebInfo -scheme obs-studio -parallelizeTargets -destination "generic/platform=macOS,name=Any Mac"

Types of changes

• Code cleanup (non-breaking change which makes code smaller or more readable)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code is not on the master branch.
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.