Add bare-bones editor UI

[appcypher]

We need to add a very basic editor UI based on Monaco. This basic UI will serve as the foundation for a more-fleshed out design in the future. It is not meant to be perfect on the first run.

What are needed to achieve this:

• A mockup of the basic UI
• Add monaco-editor to the project to take advantage of editor utils
• Add react and mobx for UI design and state management
• Design a basic editor UI with the following components:
  • Sidebar
  • Editor
  • Status bar
  • Action bar
  • Panels
• Integrate some monaco editor features