I can tell when there is new activity in the transactions list, no matter where I am in the app (e.g. a visual indicator)

[Radosław Szpiech]

Created from #488. As for now there is no indicator that there is new activity on transaction list. When new transaction comes, then the app is filled with transaction approval modal, which we can approve or reject, so we know about this transaction, but there is no separate indicator that it appeared on the list.

To be decided if we want it to be implemented, and how.