Exposer select widget for "Add existing node"

Problem/Motivation

At the moment the select list for existing nodes is a 2 click venture behind an unnecessary button. Also it would make more sense from a UX perspective to have the option to select existing before creating a new entity so layout for this would be [Select existing ] or [Add new ].

Current Problem

Also [Add node] as a confirmation seems superfluous and confusing to a user if they've already selected the item the found in the list.

User interface changes

[Select existing ] or [Add new ]