tlv+go.mod: generate inbound fee TLV type

Also add a temporariy replace to the tlv package which can be removed as
soon as the PR that includes this commit is merged and a new tag for the
tlv package has been created.

tlv/internal/gen/gen_tlv_types.go

@@ -22,6 +22,10 @@ const (
 	// second defined unsigned TLV range used in pure TLV messages.
 	pureTLVSecondUnsignedTypeRangeStart uint32 = 3000000000
 
+	// inboundFeeType defines the TLV type used within the channel_update
+	// message to indicate the inbound fee for a channel.
+	inboundFeeType = 55555
+
 	defaultOutputFile = "tlv_types_generated.go"
 )
 
@@ -29,6 +33,7 @@ const (
 var typeMarkers = map[uint32]struct{}{
 	pureTLVSecondSignedTypeRangeStart:   {},
 	pureTLVSecondUnsignedTypeRangeStart: {},
+	inboundFeeType:                      {},
 }
 
 const typeCodeTemplate = `// Code generated by tlv/internal/gen; DO NOT EDIT.

tlv/tlv_types_generated.go

@@ -3012,6 +3012,16 @@ func (t *tlvType300) tlv() {}
 
 type TlvType300 = *tlvType300
 
+type tlvType55555 struct{}
+
+func (t *tlvType55555) TypeVal() Type {
+	return 55555
+}
+
+func (t *tlvType55555) tlv() {}
+
+type TlvType55555 = *tlvType55555
+
 type tlvType65536 struct{}
 
 func (t *tlvType65536) TypeVal() Type {