Fix lookup relationship fields (lurf) in service catalog forms

[luis-almeida]

Description

1. organizationField was not passed to the TicketField component as it was marked as an "optional"
2. The problem was that inside the TicketField component we checked if organizationField !== null when building up the API endpoint and since organizationField was undefined it resulted in broken API calls:

This PR addresses this issue and just passed organizationField={null} since the "organization field" is a standard field and can't be added to a Service Catalog Item form.

Checklist

• 📗 all commit messages follow the conventional commits standard
• ⬅️ changes are compatible with RTL direction
• ♿ Changes to the UI are tested for accessibility and compliant with WCAG 2.1.
• 📝 changes are tested in Chrome, Firefox, Safari and Edge
• 📱 changes are responsive and tested in mobile
• 👍 PR is approved by @zendesk/vikings

[BrunoBFerreira]

Looks good. Are there any unit tests we could add for this?

[luis-almeida]

Are there any unit tests we could add for this?

Where would you add you add it?

[BrunoBFerreira]

Are there any unit tests we could add for this?

Where would you add you add it?

I think maybe we could check if the form is now being rendered correctly but given that now we are always passing the null value might not be an very interesting test. What do you think?