Bug 35262: Improve OPAC self registration confirmation page

Bug 35262: Improve OPAC self registration confirmation page

This patch corrects logic in the OPAC self registration confirmation
template so that the right column markup is shown when various
combinations of OpacNav, OpacNavBottom, and OpacNavRight are displayed.

To test, apply the patch and enable the PatronSelfRegistration system
preference, and deactivate the PatronSelfRegistrationVerifyByEmail
preference.

- Go to the OPAC and start the process of registering online.
- Fill in the form and submit it.
- On the registration confirmation page, check that the layout looks
  correct.
- Test with the presence of various combinations of OpacNav,
  OpacNavBottom, and OpacNavRight HTML customizations.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 64edb692458262133818553c4cbfa86ca3612260)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>