WIP/SPIKE: converting project to atomic structure

RFC for using atomic structure (or similar) for this project. Seems potentially more rational than the current structure. This could be the solution, but is as much a prompt to start thinking about making this codebase more modular and easy to navigate.

Worked off of this: Atomic Design Example

Good learnings here: Rethinking-atomic-design-react-projects

Please look through -- used the ./home/ChatList screen as the prototype that calls into atomic structure -- would love feedback; suggestions; and glad to integrate thinking.

Of course this is just the beginning, as part of the atomic design principles is to generalize things for resuse so something like ChatListSwipeable could be refactored to ListSwipeable and any chat specific functionality could be drawn out into hooks/HOCs or something similar.

Cheers & look forward to feedback!

Test:

git fetch --all &&
git checkout atomic-structure &&
yarn &&
yarn ios

or yarn start and open app on simulator