Event graph view

[tboby]

Features:

• [x] Generate a graph view for events in the current file
• [x] Generate a graph view for events referenced (or referenced by) events in the current file
• [x] Draw edges from events to events they trigger
• [ ] Display the event id and event comment above each event
• [x] On clicking an event, go to it in code
• [x] On hovering over an event, show all used/set scopes
• [x] On pressing a button, export the graph to an image
• [x] On pressing a button, export the graph to json
• [x] Generate a graph view for the given saved json

Proposed graph return structure

type GraphDataItem = 
{
    id : string
    displayName : string option
    documentation : string option
    references : string list
    location : range option
    details : Map<string, string list> option
}