feature: define new feature bit for bolt11 blinded paths

We need a new feature bit for BOLT11 invoices in order to indicate that
they contain the new blinded path tagged field. Tagged fields pre-date
TLV and so nodes who dont understand them will simply skip them.
Therefore the feature bit helps them to fail fast.

feature/manager.go

@@ -128,6 +128,8 @@ func newManager(cfg Config, desc setDesc) (*Manager, error) {
 			raw.Unset(lnwire.MPPRequired)
 			raw.Unset(lnwire.RouteBlindingOptional)
 			raw.Unset(lnwire.RouteBlindingRequired)
+			raw.Unset(lnwire.Bolt11BlindedPathsOptional)
+			raw.Unset(lnwire.Bolt11BlindedPathsRequired)
 			raw.Unset(lnwire.AMPOptional)
 			raw.Unset(lnwire.AMPRequired)
 			raw.Unset(lnwire.KeysendOptional)
@@ -187,6 +189,8 @@ func newManager(cfg Config, desc setDesc) (*Manager, error) {
 		if cfg.NoRouteBlinding {
 			raw.Unset(lnwire.RouteBlindingOptional)
 			raw.Unset(lnwire.RouteBlindingRequired)
+			raw.Unset(lnwire.Bolt11BlindedPathsOptional)
+			raw.Unset(lnwire.Bolt11BlindedPathsRequired)
 		}
 		for _, custom := range cfg.CustomFeatures[set] {
 			if custom > set.Maximum() {