Implement selected domain UI

[ovitrif]

Resolves #17901

This PR:

• ★ Implements the logic to highlight the selected domain on the UI
• ⊕ Updates the global primary color in dark mode to conform with the design system
• ⊕ Updates the leading and bottom paddings for domain title to match the design

🌑	🌞

To Test

Prerequisite

◐ Toggle the SiteCreationDomainPurchasingFeatureConfig flag

1. Go to Me → App Settings → Debug settings
2. Scroll to the Features in development section
3. Tap on the item corresponding to the flag
4. Tap RESTART THE APP button

● Treatment Variation · flag ON

• Verify UI for selected domain matches the design specs

  1. See prerequisite
  2. Go to My Site
  3. Tap the ↓ arrow at the right of the site name
  4. Tap the + at the top right
  5. Tap the ⊕ Create WordPress.com site button
  6. Skip steps 1 and 2
  7. Enter a text to get domain suggestions
  8. ✅ Tap a few items and compare app's UI vs UI design

Regression Notes

1. Potential unintended areas of impact
   N/a - new functionality behind feature flag

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   Manual testing and unit testing

3. What automated tests I added (or what prevented me from doing so)
   Unit test in SiteCreationDomainsViewModelTest

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

n/a UI Changes testing checklist

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr18295-51f154c
	Commit	51f154c
	Direct Download	wordpress-prototype-build-pr18295-51f154c.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr18295-51f154c
	Commit	51f154c
	Direct Download	jetpack-prototype-build-pr18295-51f154c.apk

Note: Google Login is not supported on these builds.

[mkevins]

These changes look good, and the code changes look great. Nice work Ovi!

A minor observation I had (though seemingly unrelated with this PR): When I have selected a domain, and then tap back to go back to the theme selection screen, pick a theme again, and return back to the domain search screen, the search input is empty, but the previous results (including the selected domain) are still present. Also, the "Purchase domain" button is still visible. Maybe this is expected, but it felt weird since the search input was still empty. Is this expected behavior?

[ovitrif]

When I have selected a domain, and then tap back to go back to the theme selection screen, pick a theme again, and return back to the domain search screen, the search input is empty, but the previous results (including the selected domain) are still present. Also, the "Purchase domain" button is still visible. Maybe this is expected, but it felt weird since the search input was still empty.

Thank you for finding this and reporting it @mkevins 🙇🏻 !

Is this expected behavior?

It doesn't feel "expected" to me, but upon checking in production I found it repro's:

🎬 Prod repro scenario

rec.mp4

Given the fact that it's in production for a long time, my suggestion going forward is to ignore it for now (cc. @antonis) 🙏🏻

[antonis]

my suggestion going forward is to ignore it for now

I agree that this should not be blocking 👍 Let's open an issue to track this down thought.

[mkevins]

I agree that this should not be blocking 👍 Let's open an issue to track this down thought.

I've opened an issue to track this: #18311