multi: move failed attempt cfg option to the router subsytem

Previously we had db and application logic mixed on the db level.
We now move the config option KeepFailedPaymentAttempts to the
ChannelRouter level and move it out of the db level.

config_builder.go

@@ -1236,9 +1236,6 @@ func (d *DefaultDatabaseBuilder) BuildDatabase(
 		// will build a SQL payments backend.
 		sqlPaymentsDB, err := d.getPaymentsStore(
 			baseDB, dbs.ChanStateDB.Backend,
-			paymentsdb.WithKeepFailedPaymentAttempts(
-				cfg.KeepFailedPaymentAttempts,
-			),
 		)
 		if err != nil {
 			err = fmt.Errorf("unable to get payments store: %w",
@@ -1280,9 +1277,6 @@ func (d *DefaultDatabaseBuilder) BuildDatabase(
 		// Create the payments DB.
 		kvPaymentsDB, err := paymentsdb.NewKVStore(
 			dbs.ChanStateDB,
-			paymentsdb.WithKeepFailedPaymentAttempts(
-				cfg.KeepFailedPaymentAttempts,
-			),
 		)
 		if err != nil {
 			cleanUp()