API Umbrella Backend ID not saved when submitting API Backend via wizard

[brylie]

The API Backend Wizard savves the API Backend directly from the form. This means the returned API Backend object, from API Umbrella, is disgarded. Make sure to save the returned API Backend object, rather than the form submission, so that we get a reference to the API Umbrella Backend ID and other metadata.

[brylie]

Closed via PR #741