Combine BalanceHeader and BalanceHeaderFiat into a cleaner, unit-tested component. Implement in App.js so it appears in the same position for all screens.
Note: This means the Settings screen how has the BalanceHeader at the top which, imo, is an improvment.
Features of new BalanceHeader
- Hidden balance now controlled by css and not component replacement (faster)
- Support for different user locale number formatting
- Decimal places are now always constant (i.e. 2 decimal places for fiat and XEC, not sometimes 1)
- Unit tested component
- Unit tests for App.js