Feature/code split reducers

[edbrett]

Overview

Sometimes in life things don't turn out the way you expect them too. This can be something you realise slowly, over many years as your life gently slips into a montage of desperate chaos. It can also happen suddenly and abruptly. Like when @sorodrigo informs you that you don't know cheese about code splitting and ES6 imports and you have been importing your entire reducer tree into you main app pack all along and your entire app is a lie.

Unlike a messy and problematic life full of poor choices, code splitting reducers isn't actually that hard. It took a similar amount of emotional effort to fix but with this PR both GFWs life and code splitting are back on track.

Core therapy methods have been:

• splitting reducers using a registry in the app folder
• refactor selectors to handle dynamic reducers

TODO:

• Split map menu so that is isn't importing actions into the root.
• Events for new module maps