A4A: Use countryOptions so the form sends country codes instead of labels

[tiagonoronha]

Part of https://linear.app/a8c/issue/A4A-1829/add-country-code-country-code-iso2-field-to-hubspot-forms

Proposed Changes

• Replace the custom label-only list with countryOptions so the form submits country codes.

Why are these changes being made?

• To start submitting the actual country codes, which is what we want to store in the HubSpot form.

Testing Instructions

• Apply this PR to your sandbox: 196289-ghe-Automattic/wpcom
• Open the live link
• Go to https://agencies.automattic.com/marketplace/hosting/refer-enterprise-hosting
• Submit the form.
• Check HubSpot Forms → Qualifying Leads submissions and confirm the Country Code (ISO2) field is populated correctly.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you tested accessibility for your changes? Ensure the feature remains usable with various user agents (e.g., browsers), interfaces (e.g., keyboard navigation), and assistive technologies (e.g., screen readers) (PCYsg-S3g-p2).
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-162247

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-162247&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-162247&env=a8c-for-agencies

[vitozev]

LGTM!