LP#1681466: move text to body of confirm dialog and add title

LP#1681466: move text to body of confirm dialog and add title

This patch tweaks the opt-in confirm dialog to add a
title and move the text to the body of the dialog, making it
consistent with other dialogs that ask long questions.

Test case for the entire bug fix
--------------------------------
[1] Ensure that <opt_in> is set to true in opensrf.xml.
[2] In the web staff client, open the checkout page
    and do a barcode search for a patron is *not* the
    same system as the workstation that the staff user
    is registered to.
[3] Verify that a dialog box is presented asking the
    staff user to confirm that personal information can be
    shared with the workstation's library.

Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>