fix: destructure formState properties to enable proper Proxy subscription

[Umesh-Tiruvalluru]

What does this PR do?

Fixes #25208

Destructures formState properties (isDirty, isSubmitting, isValid, errors) at the component level instead of accessing them directly through the form object.

Per react-hook-form's documentation, formState is wrapped with a Proxy and properties must be destructured to enable proper subscription and re-renders. The same fix was already applied in #25197 for routing forms — this PR extends it to all remaining instances.

Affected files:

• AgentConfigurationSheet.tsx — isDirty (two forms)
• WorkflowPage.tsx — isDirty
• EventTypeLayout.tsx — isDirty
• IntegrationAttributeSyncCard.tsx — isDirty
• WebhookForm.tsx — isDirty
• AvailabilitySettings.tsx — isDirty
• PasswordView.tsx — isDirty, isSubmitting
• AdminUser.tsx — isValid, isSubmitting
• LicenseSelection.tsx — isValid
• EditLocationDialog.tsx — errors

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• N/A — no documentation changes required.
• N/A — this is a refactor that ensures correct Proxy subscription, not a behavior change. Existing tests cover form functionality.

How should this be tested?

• No environment variables needed
• Navigate to any of the affected pages (Event Type settings, Webhooks, Availability, Workflows, Password settings)
• Verify forms load without console errors
• Verify Save/Submit buttons correctly enable when form is dirty and disable when form is clean

[CLAassistant]

All committers have signed the CLA.

[cubic-dev-ai]

No issues found across 11 files