Add ability to select nodes in nodeGraph via name search

[bentoogood]

Yuta's found he's got quite a few a nodes now, and thought in future when we get even more complex graphs that some search functionality might be helpful.

So how's about ctrl+f type node name selects nodes that match?

[johnhaddon]

Sounds fine. Do we also want search by type so you can easily find all the read nodes and suchlike? And search by shader type too since all shaders for a particular renderer are held on the same sort of node?

Before we go down this road though it might be worth checking out the Browser panel - it can browse nodes and there is some filtering in there so it might be useful for this sort of task. I'd be interested to see if refinements to that might be preferred over separate search functionality...