Visualizer enhancements

[farskid]

This PR:

• Separates Visualizer component
• Separates EditorRenderer component which is responsible for rendering the editor
• Creates a version of visualizer without the editor

The part that creates two versions of the visualizer, one with the editor and one without, is still a work in progress. I'll clean up with more reusability in mind.

fixes https://github.com/statecharts/xstate-viz/issues/17

Chores:

• Update XState to v4.5

[farskid]

I'm thinking about keeping statecharts with and without editor separately but another way to tackle it would be to have a withEditor: boolean prop on the StateChart component to support both.

[coodoo]

to have a withEditor: boolean prop on the StateChart component to support both.

+100 for having a falg to show/hide the editor! 🙌

[davidkpiano]

This looks great! Hopefully it won't conflict too much with my local changes, but if it does, I'll merge parts of yours in locally.

[farskid]

@coodoo ok I'll change it to a single component with that flag. Also thinking about adding a toggle editor button next to reset button just in case people wanna see the editor in action.

[farskid]

@davidkpiano I'm sure we can work it out :)

[farskid]

@davidkpiano This should be now ready to ship. Side note: I'll work on Monaco editor in a separate PR. Tried adding it to the same branch, but Monaco needs some voodoo magic to get web workers running with Rollup.