Avoid crash when editing response method (#3442)

When submitting self-consent via Gillick assessment, we should be able
to change the response method without the service displaying an error
page.

At the moment, this takes the user back through the entire flow, but
this is the case for all the other change links so I think that should
be fixed in a further enhancement. Also, going back through the entire
journey is currently the only way to change whether the parents should
be notified or not so some design work is needed as well.

[Jira Issue](https://nhsd-jira.digital.nhs.uk/browse/MAV-966)

Author: thomasleese

app/views/draft_consents/confirm.html.erb

@@ -14,8 +14,8 @@
 <%= render AppCardComponent.new do |card| %>
   <% card.with_heading { "Consent" } %>
   <%= render AppConsentSummaryComponent.new(@draft_consent, change_links: {
-                                                              response: wizard_path(:agree),
-                                                              route: wizard_path(:route),
+                                                              response: wizard_path("agree"),
+                                                              route: wizard_path(@draft_consent.via_self_consent? ? "who" : "route"),
                                                             }) %>
 <% end %>
 

spec/features/self_consent_spec.rb

@@ -199,6 +199,10 @@ def and_the_child_can_give_their_own_consent_that_the_nurse_records
     click_on "Continue"
 
     # confirmation page
+    click_on "Change response method"
+    choose "Child (Gillick competent)"
+    5.times { click_on "Continue" }
+
     click_on "Confirm"
 
     expect(page).to have_content("Consent recorded for #{@patient.full_name}")