multi: extract wallet initialization

With this commit we extract the wallet creation/unlocking and
initialization completely out of the main function. This will allow us
to use custom implementations in the future.

chainreg/chainregistry.go

@@ -34,6 +34,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing/chainview"
+	"github.com/lightningnetwork/lnd/walletunlocker"
 )
 
 // Config houses necessary fields that a chainControl instance needs to
@@ -79,6 +80,10 @@ type Config struct {
 	// BlockCache is the main cache for storing block information.
 	BlockCache *blockcache.BlockCache
 
+	// WalletUnlockParams are the parameters that were used for unlocking
+	// the main wallet.
+	WalletUnlockParams *walletunlocker.WalletUnlockParams
+
 	// NeutrinoCS is a pointer to a neutrino ChainService. Must be non-nil if
 	// using neutrino.
 	NeutrinoCS *neutrino.ChainService