Adds check your answers form

This form doesn't perform any validations and save isn't called on the
form so we have an empty form object, however this form object is still
required. The check your answers page is submitted to the claim
submission controller, which does perform validations, and if the
validation fails the check your answers rerenders with the claim
submission form. Rather than mapping "check-your-answers" to the
`ClaimSubmissionForm` we instead use the "empty" `CheckYourAnswersForm`
so we can avoid changing the api of the `ClaimSubmissionForm` just to
make it compatable with the `Form` base class, ie the
`ClaimSubmissionForm` doesn't need any of the parameters passed to `Form`
subclasses in `Journeys::Base` module, it just needs an instance of
`Journeys::Session`.

Also of note we've had to introduce a conditional in the
BaseAnswersPresenter as we need this to work with both a `CurrentClaim`
and a `Claim`. When dealing with a `CurrentClaim` (`check-your-answers`
rendered from the `ClaimController#show`) we can't always assume the
eligibility is eligible. We also rander the `check-your-answers` page
from the `SubmissionController#create` action if the form is invalid, in
which case we'll be working with a `Claim`. We want to avoid adding
`eligible_eligibility` to the `Claim`. Once we've removed `CurrentClaim`
we can remove this conditional.

app/controllers/submissions_controller.rb

@@ -18,7 +18,6 @@ def create
       clear_claim_session
       redirect_to claim_confirmation_path
     else
-      current_claim.valid?(:submit)
       render "claims/check_your_answers"
     end
   end

app/forms/check_your_answers_form.rb

@@ -0,0 +1,2 @@
+class CheckYourAnswersForm < Form
+end

app/models/journeys/base.rb

@@ -16,7 +16,8 @@ module Base
       "personal-bank-account" => BankDetailsForm,
       "building-society-account" => BankDetailsForm,
       "teacher-reference-number" => TeacherReferenceNumberForm,
-      "address" => AddressForm
+      "address" => AddressForm,
+      "check-your-answers" => CheckYourAnswersForm
     }
 
     def configuration

app/models/journeys/base_answers_presenter.rb

@@ -4,7 +4,12 @@ class BaseAnswersPresenter
 
     def initialize(claim)
       @claim = claim
-      @eligibility = claim.eligible_eligibility
+
+      @eligibility = if @claim.is_a?(CurrentClaim)
+        claim.eligible_eligibility
+      else
+        claim.eligibility
+      end
     end
 
     def identity_answers

app/views/additional_payments/claims/check_your_answers.html.erb

@@ -1,16 +1,25 @@
-<% content_for(:page_title, page_title("Check your answers before sending your application", journey: current_journey_routing_name, show_error: current_claim.errors.any?)) %>
+<% content_for(
+  :page_title,
+  page_title(
+    "Check your answers before sending your application",
+    journey: current_journey_routing_name,
+    show_error: @form.errors.any?
+  )
+) %>
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
-    <%= render("shared/error_summary", instance: current_claim) if current_claim.errors.any? %>
+    <% if @form.errors.any? %>
+      <%= render("shared/error_summary", instance: @form) %>
+    <% end %>
 
     <h1 class="govuk-heading-xl">
       Check your answers before sending your application
     </h1>
 
-    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Identity details", answers: journey.answers_for_claim(current_claim).identity_answers} %>
+    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Identity details", answers: journey.answers_for_claim(@form.claim).identity_answers} %>
 
-    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Payment details", answers: journey.answers_for_claim(current_claim).payment_answers} %>
+    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Payment details", answers: journey.answers_for_claim(@form.claim).payment_answers} %>
 
     <%= form_with url: claim_submission_path do |form| %>
       <h2 class="govuk-heading-m"><%= t("additional_payments.check_your_answers.heading_send_application") %></h2>

app/views/student_loans/claims/check_your_answers.html.erb

@@ -1,18 +1,27 @@
-<% content_for(:page_title, page_title("Check your answers before sending your application", journey: current_journey_routing_name, show_error: current_claim.errors.any?)) %>
+<% content_for(
+  :page_title,
+  page_title(
+    "Check your answers before sending your application",
+    journey: current_journey_routing_name,
+    show_error: @form.errors.any?
+  )
+) %>
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
-    <%= render("shared/error_summary", instance: current_claim) if current_claim.errors.any? %>
+    <% if @form.errors.any? %>
+      <%= render("shared/error_summary", instance: @form) %>
+    <% end %>
 
     <h1 class="govuk-heading-xl">
       Check your answers before sending your application
     </h1>
 
-    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Eligibility details", answers: journey.answers_for_claim(current_claim).eligibility_answers} %>
+    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Eligibility details", answers: journey.answers_for_claim(@form.claim).eligibility_answers} %>
 
-    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Identity details", answers: journey.answers_for_claim(current_claim).identity_answers} %>
+    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Identity details", answers: journey.answers_for_claim(@form.claim).identity_answers} %>
 
-    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Payment details", answers: journey.answers_for_claim(current_claim).payment_answers} %>
+    <%= render partial: "claims/check_your_answers_section", locals: {heading: "Payment details", answers: journey.answers_for_claim(@form.claim).payment_answers} %>
 
     <%= form_with url: claim_submission_path do |form| %>
       <h2 class="govuk-heading-m"><%= t("check_your_answers.heading_send_application") %></h2>