Bug 35445: Require OPAC user to confirm self-registration with button push

Bug 35445: Require OPAC user to confirm self-registration with button push

This change requires the OPAC user to confirm self-registration with
a button push when verifying registration using an emailed token.

Test plan:
0. Apply the patch and koha-plack --reload kohadev
1. Set syspref PatronSelfRegistrationVerifyByEmail to "Don't require"
2. Create a patron using the self-registration on the OPAC
3. Note that no confirmation step is needed when self-registering
4. Set syspref PatronSelfRegistrationVerifyByEmail to "Require"
5. Create a patron using the self-registration on the OPAC
6. Look in message_queue to find the URL with the token to
visit in the browser
7. Visit that URL
8. Note that the page says "Registration pending" and asks you to
click a button labeled "Confirm"
9. Click the button labeled "Confirm"
10. Note that the self-registration is confirmed and details are
shown on the page

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>