Bug 25251: Remove alert from disabled buttons

Bug 25251: Remove alert from disabled buttons

This patch removes the alert, but adds a stopPropagation call
in order to not close the menu when the disabled buttons are clicked

To test:
1 - Find a record with items in the staff interface
2 - Click edit
3 - Note 'Edit items in a batch, 'Delete items in a batch', and 'Delete
    all items' are grayed out
4 - Note hovering displays a note that there are no items
5 - Click on each anyway, an alert is generated, menu is closed
6 - Apply patch
7 - Reload page
8 - Click on each disabled option and confirm
    - there is no more alert
    - the menu does not close
9 - Confirm tooltip is displayed

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>