Bug 9032: (follow-up) adjust the "share a list" template

Bug 9032: (follow-up) adjust the "share a list" template

This patch makes a few changes to the "share a list" template:

- We don't use tables for layout of forms. This patch corrects the
  display of the share form to use Koha standard form markup.
- Revise the confirmation message displayed after a list is shared to be
  more readable.
- Add a link back to private lists to the confirmation message.
- Add T:T markup to make this page display the left-hand navigation
  which is shown on other patron-related pages when a user is logged in.

To test, apply this patch on top of other patches pending for Bug 9032
and confirm that the list share form looks correct and works correctly.
Confirm that share confirmation page reads well.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Dobrica Pavlinusic <dpavlin@rot13.org>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>