list sharing implemented w. passing UTs & FTs; changes to apps.dashboard.urls, .models, .views & .tests.test_views to accomodate; functional_tests.test_sharing also ensures sharing visible in UX; templates/apps/dashboard/list.html & /my_lists.html updated with django templating & for loops

src/templates/apps/dashboard/list.html

@@ -11,6 +11,7 @@
 
 {% block content %}
     <div class="row justify-content-center">
+        <small>List created by: <span id="id_list_owner">{{ list.owner.email }}</span></small>
         <div class="col-lg-6">
             <table id="id_list_table" class="table">
                 {% for item in list.item_set.all %}
@@ -19,6 +20,35 @@
             </table>
         </div>
     </div>
+
+    <div class="row justify-content-center">
+        <div class="col-lg-6">
+
+            <form method="POST" action="{% url "share_list" list.id %}">
+                {% csrf_token %}
+                <input
+                    id="id_recipient"
+                    name="recipient"
+                    class="form-control form-control-lg{% if form.errors %} is-invalid{% endif %}"
+                    placeholder="friend@example.com"
+                    aria-describedby="id_recipient_feedback"
+                    required
+                />
+                {% if form.errors %}
+                    <div id="id_recipient_feedback" class="invalid-feedback">
+                        {{ form.errors.recipient.0 }}
+                    </div>
+                {% endif %}
+
+                <button type="submit" class="btn btn-primary">Share</button>
+            </form>
+            <small>List shared with:
+                {% for user in list.shared_with.all %}
+                    <span class="list-recipient">{{ user.email }}</span>
+                {% endfor %}
+            </small>
+        </div>
+    </div>
 {% endblock content %}
 
 {% block scripts %}