[DI-29309] - Create Notification Channel label error validation

[santoshp210-akamai]

Description 📝

Fix to process API errors for label field in Notification Channel Create form

Changes 🔄

List any change(s) relevant to the reviewer.

• Rename name to label within the CreateNotificationChannelForm interface context

Scope 🚢

Upon production release, changes in this PR will be visible to:

• All customers
• Some customers (e.g. in Beta or Limited Availability)
• No customers / Not applicable

Target release date 🗓️

10th Feb

Preview 📷

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Before	After

How to test 🧪

Prerequisites

(How to setup test environment)

• In Mock environment (Legacy MSW Handlers),
• Click on Alerts, under Monitor
• Enable the notificationChannels options within the aclpAlerting(CloudPulse Alerting) feature flag
• Click on Notification Channel Tab
• Click on Create button
• Paste this return HttpResponse.json({errors: [{ field: 'label', reason: 'Label is already taken.'}]}, {status: 400}); in the '*/monitor/alert-channels' POST method in serverHandler.ts to simulate the error condition

Verification steps

(How to verify changes)

• API errors with field label is visible in the form

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

[linode-gh-bot]

Cloud Manager UI test results

🔺 1 failing test on test run #5 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
1 Failing	864 Passing	11 Skipped	35m 34s

Details

Failing Tests
	Spec	Test
❌	clone-linode.spec.ts	Cloud Manager Cypress Tests→clone linode » can clone a Linode from Linode details page

Troubleshooting

Use this command to re-run the failing tests:

pnpm cy:run -s "cypress/e2e/core/linodes/clone-linode.spec.ts"

[santoshp210-akamai]

Merging this PR as the failing cypress test is not related to the PR changes.