test: add error-handling and sensitive key protection tests for ApiKeySetupModal (#1411)

[Rakshak05]

Description

This PR adds unit tests for ApiKeySetupModal to verify robust error-handling behavior when the API key setup fails. The new tests verify:

• Accurate rendering of the dialog UI under standard conditions.
• Validation message triggering on empty key submissions.
• Rendering of backend-provided error messages upon validation rejection.
• Prevention of sensitive key exposure: checking that the sensitive API key text is never echoed back in the failure alert UI or printed to console streams (console.log, console.warn, console.error).

Related Issues

• Closes [TEST] Add ApiKeySetupModal error-handling tests #1411

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

We validated these changes by executing the unit tests locally:

1. Navigated to frontend
2. Ran: npm run test -- ApiKeySetupModal.test.tsx
3. All 5 tests passed successfully.

Checklist

• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.