frontend: Add support for TEB/Multitrack Video to macOS (arm64 only)

[dsaedtler]

Description

Adds TEB support for macOS on Apple Silicon.

Motivation and Context

Want to support all users, including macOS/Linux (Linux tbd).
The small number of SKUs makes Apple Silicon easy, and since Intel Macs are losing support it seems fine to only support ARM.

Note: GetClientConfiguration API changes have not yet rolled out into production.

How Has This Been Tested?

Locally with Twitch staging environment.

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

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

[dsaedtler]

Configuration API support for macOS is now rolling out into production, within the next few days this PR should be testable by anyone.

[dsaedtler]

The server-side changes have now rolled out, so this PR can be tested by anybody who wishes to do so!

[RytoEX]

We should probably add a license header to frontend/utility/system-info-macos.mm. That need not be done here, but it would be fine to include here.

Prefix should be frontend: .

@PatTheMav I'd appreciate a quick glance to make sure the includes/imports are as preferred.