Refactor components to a simpler styling method
All components no longer 'appear' as a Material-UI component (removed custom Ucam classes and material typescript module augmentation). This removes a lot boilerplate involved in creating new components, and also removes the ability for consumers of our design system to deeply customise all aspects of the component. We've decided that we don't want this level of customisation as our design system should provide constraints that enforce our design language.
All styling for our components now uses the experimentalStyled api provided by material, which is actually a light abstraction over Emotion. The theme file should now only be used to override styles of Material-UI components, and not our own custom ones.
I've included a small contributing doc that gives an example of which styling approach to choose.
Acceptance:
- All components should function exactly as before
- Components should no longer be able to be styled from the theme
styleOverridespattern - Contributing doc should make sense
Closes #44 (closed) #45 (closed)
