cln: Add serialization of the getswap command return

The enums role and type have been returned as int values. For
a better human readability we now return them as string

clightning/clightning_commands.go

@@ -596,7 +596,7 @@ func (g *GetSwap) Call() (jrpc2.Result, error) {
 	if err != nil {
 		return nil, err
 	}
-	return swap, nil
+	return MSerializedSwapStateMachine(swap), nil
 }
 
 func (g *GetSwap) Get(client *ClightningClient) jrpc2.ServerMethod {

clightning/serializing.go

@@ -0,0 +1,19 @@
+package clightning
+
+import "github.com/elementsproject/peerswap/swap"
+
+// SerializedSwapStateMachine is the serialized representation of the internal
+// state machine with all these massive (and unnecessary) amounts of data.
+type SerializedSwapStateMachine struct {
+	*swap.SwapStateMachine
+	Type string `json:"type"`
+	Role string `json:"role"`
+}
+
+func MSerializedSwapStateMachine(swapStateMachine *swap.SwapStateMachine) *SerializedSwapStateMachine {
+	return &SerializedSwapStateMachine{
+		SwapStateMachine: swapStateMachine,
+		Type:             swapStateMachine.Type.String(),
+		Role:             swapStateMachine.Role.String(),
+	}
+}