feat: connect project and scenario routers to new Jinja2 views with forms and error handling

templates/projects/form.html

@@ -19,6 +19,10 @@
     </div>
   </header>
 
+  {% if error %}
+    <div class="alert alert-error">{{ error }}</div>
+  {% endif %}
+
   <form class="form" method="post" action="{{ form_action }}">
     <div class="form-group">
       <label for="name">Name</label>