Always display Index 0 Address on Coin Control (and label "Wallet Connect")

Also, consider adding it to the list of "pinned addresses" that is always scanned, even if it has the exact 2 count.

For the time being, people are still using WalletConnect, and index 0 is more important than it generally should be, so best to help users with that experience as much as possible until the ecosystem has moved away from it entirely.