Cannot create new instance in related instance widget when target model has high number of instances

[chiatt]

When trying to create a new instance using the related instance widget, the button to create a new instance is at the bottom of the list. If there is a long list of relatable instances, scrolling down to the new instance button can take a long time. If there is a a very long list (> 1000) the button is basically unavailable.

The create new instance button should be visible regardless of how many instances are available in the drop down.

[chiatt]

This problem is actually resolved by a user searching for an existing resource. If none is found, the create new instance button is visible. Offering this workflow to users helps prevent the creation of duplicate instances.