CA-136783: Fixed the errors in the Updates window, where clicking "Go to Web Page" opens a wrong link


- When clicking the action button on the grid, execute the action on the item that has been clicked, instead on using the grid's selected item, which may have not been updated yet.
- On multiselect (if the multiselect is allowed for the action), if the clicked item is in the grid's selection list, then execute the action on the whole list, otherwise on the clicked item only.
- This applies to both Updates and Alerts windows.

Signed-off-by: Mihaela Stoica <mihaela.stoica@citrix.com>