add choose friend to group chats

sessiondetailwidget.h

@@ -12,6 +12,7 @@
 
 #include "debug.h"
 #include "model/data.h"
+#include "choosefrienddialog.h"
 
 using namespace model;
 
@@ -22,6 +23,10 @@ class AvatarItem : public QWidget {
 public:
     AvatarItem(const QIcon& avatar, const QString& name);
 
+    QPushButton* getAvatar() {
+        return avatarBtn;
+    }
+
 private:
     QPushButton* avatarBtn;
     QLabel* nameLabel;