BIP44 - Scan for change and index level addresses that have a balance

[lauhon]

Currently we are deriving exactly one address at path m/84'/0'/0'/0/0.

Bitcoins UTXO "Architecture" actually is laid out in a way to have many addresses that can hodl a balance for more privacy.
We should support this in some way.

Either automatically create new addresses every time we open the receive screen and for the change of a new outgoing transaction. Or only when the user explicitly wishes to do so (?)