Wallet 2020 main screen, store and Tokens tab behind a FF

• Move params definitions for stack navigators to the correct ones
• Move settings items to generic menu components and fix minor style problems
• Create a title component for the menus
• Implement a reusable tab bar component with subtitle support and typed ids
• Implement a reusable button tab bar component
• Build the wallet screen layout behind a wallet feature flag
• Plotly was added but finally had to remove it because of performance issues
• Implement the Tokens tab
• Implement token overview component
• Wallet setup and actions menu
• Create the main wallet store.

closes #2165 (closed) #2112 (closed)