Update links missed in previous work

Includes those in:
- the static 5xx error page
- validation messaging
- guidance page about trial mode
- links used in tests

Issues raised in https://github.com/alphagov/notifications-admin/pull/3303#issuecomment-589572715

app/assets/error_pages/5xx.html

@@ -75,7 +75,7 @@
               Try again later.
             </p>
             <p class="govuk-body">
-              You can check our <a href="https://status.notifications.service.gov.uk/">system status</a> page to see if there are any known issues.<br/>To report a problem, email <a href="mailto:notify-support@digital.cabinet-office.gov.uk">notify-support@digital.cabinet-office.gov.uk</a>
+              You can check our <a class="govuk-link govuk-link--no-visited-state" href="https://status.notifications.service.gov.uk/">system status</a> page to see if there are any known issues.<br/>To report a problem, email <a href="mailto:notify-support@digital.cabinet-office.gov.uk">notify-support@digital.cabinet-office.gov.uk</a>
           </div>
         </div>
       </main>

app/main/validators.py

@@ -46,7 +46,8 @@ class ValidGovEmail:
         message = (
             'Enter a government email address.'
             ' If you think you should have access'
-            ' <a href="{}">contact us</a>').format(url_for('main.support'))
+            ' <a class="govuk-link govuk-link--no-visited-state" href="{}">contact us</a>'
+        ).format(url_for('main.support'))
         if not is_gov_user(field.data.lower()):
             raise ValidationError(message)
 

app/templates/views/trial-mode.html

@@ -24,7 +24,7 @@
     To remove these restrictions:
   </p>
   <ol class="list list-number">
-    <li><a href="{{ url_for('.sign_in') }}">Sign in to Notify</a>.</li>
+    <li><a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.sign_in') }}">Sign in to Notify</a>.</li>
     <li>Go to the <b class="govuk-!-font-weight-bold">Settings</b> page.</li>
     <li>Select <b class="govuk-!-font-weight-bold">Request to go live</b>.</li>
   </ol>

app/utils.py

@@ -571,22 +571,34 @@ LETTER_VALIDATION_MESSAGES = {
         'title': 'Your letter is not A4 portrait size',
         'detail': (
             'You need to change the size or orientation of {invalid_pages}. <br>'
-            'Files must meet our <a href="{letter_spec_guidance}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec_guidance}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
         'summary': (
             'Validation failed because {invalid_pages} {invalid_pages_are_or_is} not A4 portrait size.<br>'
-            'Files must meet our <a href="{letter_spec}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
     },
     'content-outside-printable-area': {
         'title': 'Your content is outside the printable area',
         'detail': (
             'You need to edit {invalid_pages}.<br>'
-            'Files must meet our <a href="{letter_spec_guidance}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec_guidance}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
         'summary': (
             'Validation failed because content is outside the printable area on {invalid_pages}.<br>'
-            'Files must meet our <a href="{letter_spec}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
     },
     'letter-too-long': {
@@ -618,11 +630,17 @@ LETTER_VALIDATION_MESSAGES = {
         'title': 'The address block is empty',
         'detail': (
             'You need to add a recipient address.<br>'
-            'Files must meet our <a href="{letter_spec_guidance}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec_guidance}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
         'summary': (
             'Validation failed because the address block is empty.<br>'
-            'Files must meet our <a href="{letter_spec}" target="_blank">letter specification</a>.'
+            'Files must meet our '
+            '<a class="govuk-link govuk-link--no-visited-state" href="{letter_spec}" target="_blank">'
+            'letter specification'
+            '</a>.'
         ),
     }
 }

tests/app/main/views/test_user_profile.py

@@ -263,7 +263,7 @@ def test_non_gov_user_cannot_see_change_email_link(
 ):
     client_request.login(api_nongov_user_active)
     page = client_request.get('main.user_profile')
-    assert '<a href="/user-profile/email">' not in str(page)
+    assert '<a class="govuk-link govuk-link--no-visited-state" href="/user-profile/email">' not in str(page)
     assert page.select_one('h1').text.strip() == 'Your profile'