fix: [M3-9986] - Selected Geographical Area state in Distributed Region select

[hana-akamai]

Description 📝

Fix selected Geographical Area persistence issue when switching between Core and Distributed Region tabs

Preview 📷

Before	After
before.mov	after.mov

How to test 🧪

Prerequisites

(How to setup test environment)

• Ensure gecko feature flag is enabled and your account has gecko customer tags (reach out for more info)

Reproduction steps

(How to reproduce the issue, if applicable)

• Go to the Linode Create page on prod or another branch
• Click on the Distributed Region tab, select a value other than All, click on the Core Region tab, switch back to the Distributed tab
• You should see the Geographical Area changes back to All but the Regions are filtered based off the previous area selection

Verification steps

(How to verify changes)

• Checkout this branch or preview link and go to the Linode Create page
• Click on the Distributed Region tab, select a value other than All, click on the Core Region tab, switch back to the Distributed tab
• You should see the Geographical Area persist the value you selected before switching and the Regions are still filtered accordingly

Author Checklists

As an Author, to speed up the review process, I considered 🤔

👀 Doing a self review
❔ Our contribution guidelines
🤏 Splitting feature into small PRs
➕ Adding a changeset
🧪 Providing/improving test coverage
🔐 Removing all sensitive information from the code and PR description
🚩 Using a feature flag to protect the release
👣 Providing comprehensive reproduction steps
📑 Providing or updating our documentation
🕛 Scheduling a pair reviewing session
📱 Providing mobile support
♿ Providing accessibility support

• I have read and considered all applicable items listed above.

As an Author, before moving this PR from Draft to Open, I confirmed ✅

• All tests and CI checks are passing
• TypeScript compilation succeeded without errors
• Code passes all linting rules

[bnussman-akamai]

Looks good! Just left some comments with test improvements/clean up

[dwiley-akamai]

Fix confirmed & no regressions observed ✅
Code review ✅
Checks pass ✅

[linode-gh-bot]

Cloud Manager UI test results

🎉 690 passing tests on test run #3 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
0 Failing	690 Passing	4 Skipped	122m 47s