Draft: Small MR to fix the nav bar history and tidy up the accounts list on the home page

• Fixed top nav to not show back button on root elements
• Realigned items in the accounts list to make it more fluid
• resized icons all to 24dp for consistency.
• Move alert messages into a snackbar for android, iOS and JVM, this is a first revision for alerts / messages, in the future error messages for input should be part of the input box and snackbars used for results of user actions.