Create `EditorControlSocket` Plugin for the Godot Editor

I've started working on a plugin to expose editor functionality to a websocket control interface, similar to [obs-websocket](https://github.com/obsproject/obs-websocket). This will allow bidirectional communication and unlock new functionality without trying to shoehorn things into the Language Server. This plugin won't be vscode/godot-tools specific, but would allow other text editors/software to control the godot editor or react to events from it.

Some open issues can be resolved using this interface.

Uses I've thought of so far:
- open a scene file in the editor
- run a specific scene(like pressing F6)
- open a resource
- change/query editor/project settings
- have a scene tree panel in VSCode?
- filesystem stuff
- run "tools" (stuff from the Project > Tools menu)