As a user I want to restore an existing wallet and see my non-empty accounts

Precondition: the user has an existing wallet with one or multiple non-empty accounts (with balances more than zero).
The flow should be:
- the user selects Restore Existing Wallet (on the extension's first screen)
- enters a valid mnemonic / secret phrase
- enter a password
- the user arrives on Dashboard screen where he has the list of all non-empty accounts
(accounts associated with the mnemonic and having positive balances)