[Qt] disconnect peers from peers tab via context menu

- It is now allowed to disconnect peers from peers tab via
  right-click context menu. Peers are not permanently banned!

src/qt/guiutil.cpp

@@ -265,6 +265,19 @@ void copyEntryData(QAbstractItemView *view, int column, int role)
     }
 }
 
+QString getEntryData(QAbstractItemView *view, int column, int role)
+{
+    if(!view || !view->selectionModel())
+        return QString();
+    QModelIndexList selection = view->selectionModel()->selectedRows(column);
+
+    if(!selection.isEmpty()) {
+        // Return first item
+        return (selection.at(0).data(role).toString());
+    }
+    return QString();
+}
+
 QString getSaveFileName(QWidget *parent, const QString &caption, const QString &dir,
     const QString &filter,
     QString *selectedSuffixOut)