Add a design system (#34)

* Add theming system

* Add standard Button control and update RadioButtons

* Unify radiobutton with design system

* Update debug screen to have multiple views

* Add ToggleButton

* Update error controls to use design system

* Add typography to <Text> element

* Move DropdownButton into the design system

* Clean out old code

* Move Text into design system

* Add 'inverted' color palette

* Move LoadingPlaceholder into the design system

src/view/com/util/images/AutoSizedImage.tsx

@@ -9,7 +9,7 @@ import {
   View,
   ViewStyle,
 } from 'react-native'
-import {Text} from '../Text'
+import {Text} from '../text/Text'
 import {colors} from '../../../lib/styles'
 
 const MAX_HEIGHT = 300