Implement overarching mouse and keyboard event system

[Daan0709]

Is this the only component looking for key or mouse events?
I'm thinking that maybe having an overarching system to manage key and mouse event handling could be nice since a lot of repetition might happen if this is used in multiple components

I can elaborate further but maybe its better to make an issue and let it be like this for this PR, if you agree with me here

Originally posted by @Matthbo in #229 (comment)

[Matthbo]

Key/mouse event handlers are now being added and removed through the flow component and maybe other components in the future.
In order to improve upon the browser's API of handling these event, maybe it would be nice to have a separate class handle global user input and keep track of which one's are active in order to keep track of them more easily.

This also allows for better shortcut key management and such, if that is a thing we would like to have.