Extend DiscoResult type with ID, From and To fields

xmpp.go

@@ -959,6 +959,9 @@ func (c *Client) Recv() (stanza interface{}, err error) {
 						}
 
 						return DiscoResult{
+							ID:         v.ID,
+							From:       v.From,
+							To:         v.To,
 							Features:   clientFeaturesToReturn(disco.Features),
 							Identities: clientIdentitiesToReturn(disco.Identities),
 						}, nil

xmpp_disco.go

@@ -52,6 +52,9 @@ type DiscoItem struct {
 }
 
 type DiscoResult struct {
+	ID         string
+	From       string
+	To         string
 	Features   []string
 	Identities []DiscoIdentity
 }