Explicitly show ResultBuilder Node as part of execution in the UI

**Is your feature request related to a problem? Please describe.**
The result builder is technically part of the graph, but it isn't shown -- nor is its output. This can make it hard to see what a whole execution actually produced.

**Describe the solution you'd like**
The result builder node should show up under execution - along with the data observability, etc.

**Describe alternatives you've considered**
We already do this for materializers -- they are effectively have a result builder component.

**Additional context**
Would allow us to compare the output of two executions more easily.