Bug 20205: Add IDs to buttons in patron-toolbar.inc

Bug 20205: Add IDs to buttons in patron-toolbar.inc

The buttons in patron-toolbar.inc lack unique IDs, making them
hard to style/remove with CSS. This patch adds IDs to all three
buttons.

To test:
- Look in koha-tmpl/intranet-tmpl/prog/en/includes/patron-toolbar.inc
  and verify there are no IDs
- Apply the patch and look at the file again to verify the IDs have
  been added
- Test the "New patron" and "Quick add new patron" buttons to verify
  they still work as intended
- Check that the new buttons are globally unique:
  $ grep -rn "new-patron-button" *
  $ grep -rn "patron-lists-button" *

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>