Add component for authenticated experiments to ExPlat

[IanRamosC]

See related issue

Proposed changes:

• This PR implement another set of hooks and components to be used specifically for running experiments for authenticated users.

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

Does this pull request change what data or activity we track or use?

Yes. It adds a way to run A/B experiments specifically with authenticated users.

Testing instructions:

• Confirm the code looks good and it builds correctly
• Follow the test instructions in Test ExPlat implementation #37973

[github-actions]

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[CodeyGuyDylan]

Code looks good and it tested well!