Add changed values to facility update emails

When notifying contributors when facility claimants change the profile of a
facility we want to include the specific public details that were changed.

The non-standard position of the `endfor` in the plain text email template is
intentional and ensures that extra blank lines are not included.

src/django/api/mail.py

@@ -180,11 +180,19 @@ def send_claim_update_note_to_one_contributor(request, claim, contributor):
 
     facility_country = COUNTRY_NAMES[claim.facility.country_code]
 
+    changes = claim.get_changes()
+    if changes:
+        changes = [
+            '{}: {}'.format(c['verbose_name'], c['current'])
+            for c in changes
+        ]
+
     notice_dictionary = {
         'facility_name': claim.facility.name,
         'facility_address': claim.facility.address,
         'facility_country': facility_country,
         'facility_url': make_facility_url(request, claim.facility),
+        'changes': changes,
     }
 
     send_mail(

src/django/api/templates/mail/facility_claim_profile_update_contributor_notice_body.html

@@ -25,6 +25,14 @@
                 Facility URL: {{ facility_url }}
             </li>
         </ul>
+        {% if changes %}
+        <p>The following details have been changed:</p>
+        <ul>
+            {% for change in changes %}
+            <li>{{ change }}</li>
+            {% endfor %}
+        </ul>
+        {% endif %}
         <p>
             Best wishes,
         </p>

src/django/api/templates/mail/facility_claim_profile_update_contributor_notice_body.txt

@@ -9,7 +9,13 @@ The facility is:
   - Facility: {{ facility_name }}, {{ facility_address }}, {{ facility_country }}
   - Facility URL: {{ facility_url }}
 
-Best wishes,
+{% if changes %}
+The following details have been changed:
+
+  {% for change in changes %}
+  - {{ change }} {% endfor %}
+{% endif %}
 
+Best wishes,
 {% include "mail/signature_block.txt" %}
 {% endblock content %}