Create and event bus

[Dragovorn]

I believe Winry would benefit from providing event bus functionalities, they can be exposed to the end user and also used internally. Technically we could move runner functionality to be all handled via the event bus. But I think it's best to give those their own part of the lifecycle instead of turning it into event bus runs, because runners can technically fire their own events.

Must-have features:

• If a parent method is annotated as event handler it should automatically get carried over
• Event bus listener methods should be able to use the suppliers from #24

[Dragovorn]

Event bus is working really well, just need to implement: If a parent method is annotated as event handler it should automatically get carried over but I think that's a potentially large refactor to the annotation manager codebase so I might just remove that from scope.

[Dragovorn]

Just going to remove the other requirement, I like how it is currently.