Import addresses from Bitcoin Core

[C-Otto]

Is your feature request related to a problem? Please describe.
I'd like to mark addresses as owned based on data I can export from my Bitcoin Core node.

Describe the solution you'd like
Similar to the lnd support, I'd like to be able to import files that Bitcoin Core can export. Addresses in these exports should automatically be marked as owned. The description should be taken from Bitcoin Core (if set), or set to a user-provided value.

(Wouldn't it be better to label transactions and have a unique description for all addresses associated with the specific Bitcoin Core wallet?)

Describe alternatives you've considered
Manual entry, possibly using the wizard (#27).

Additional context
https://support.cryptfolio.com/i16-how-do-i-export-my-bitcoin-addresses-from-bitcoin-core
https://support.cryptfolio.com/i17-how-do-i-export-my-change-and-keypool-bitcoin-addresses-from-bitcoin-core