Add support for naming graphs

[Baste-RainGames]

This PR adds an overload to GraphVisualizerClient.Show that takes a name:

public static void Show(PlayableGraph graph, string name)

This allows users to pick a name for their graph that's shown when picking the graph in the visualizer window. It also allows updating the graph name at runtime.

We need this for our AnimationPlayer library. When debugging it, it's useful to look at the graph it produces in the graph visualizer. Enabling renaming of the visualizer makes that process easier, as we can change the name shown in the dropdown in a less intrusive way.

As an added bonus, I made the list of names sort, so it's easier to look through.