switch workspace routes and templates to Flask and Jinja

templates/base_workspace.html

@@ -0,0 +1,15 @@
+{% extends "base.html" %}
+
+{% block content %}
+
+  <div class='workspace-panel-container'>
+    <div class='col'>
+      {% include 'navigation/workspace_navigation.html.to' %}
+    </div>
+
+    <div class='col col--grow'>
+      {% block workspace_content %}{% endblock %}
+    </div>
+  </div>
+
+{% endblock %}