Implement Graph view

[shoyguer]

Is your feature request related to a problem? Please describe.
Having a way to visualise dialogue through a graph view would make it way easier, even better when you have long dialogues.

Describe the solution you'd like
To have a graph, in the style of the plugin MadTalk, but more "Godot-like". MadTalk look like an Unreal Engine 4 plugin. This means the plugin should identify changes in text and automatically adapt into graph, and changes on graph and automatically adapt into text.
For organisational purposes, each cue will have it's own "environment" or "graph". A single graph having all cues at the same time proved very messy lol

MadTalk:

Dialogue Manager WIP graph:

Describe alternatives you've considered
There are no alternatives, only other plugins. But I love this plugin too much, so I think it would be very good to have this as a feature here.

Additional context
I'm already working on a branch to add this. However, I'm still refining stuff.

[Fireye04]

So, to my understanding, GDM is made for plaintext. This is neat work, but I don't think it's likely to be upstreamed due to that, the additional maintenance costs, as well as any additional serialization past the text source that a graphical interface demands. I may be wrong there though, so take this with a grain of salt till nathan gives his input :P

[shoyguer]

Yeah, I understand if he is against this. I knew from the start this could be the case and would be a very costly branch.
I've been working on this for the past couple of weeks because it will be very useful to me in my project.