data: Update application window ui to add a search bar.

                <property name="stack">stack</property>

              </object>

            </child>

            <child>

              <object class="GtkToggleButton" id="search">

                <property name="visible">True</property>

                <property name="sensitive">False</property>

                <style>

                  <class name="image-button"/>

                </style>

                <child>

                  <object class="GtkImage" id="search-icon">

                    <property name="visible">True</property>

                    <property name="icon-name">edit-find-symbolic</property>

                    <property name="icon-size">1</property>

                  </object>

                </child>

              </object>

              <packing>

                <property name="pack-type">end</property>

              </packing>

            </child>

          </object>

        </child>

        <child>

          <object class="GtkSearchBar" id="searchbar">

            <property name="visible">True</property>

            <child>

              <object class="GtkSearchEntry" id="searchentry">

                <signal name="search-changed" handler="search_text_changed"/>

                <property name="visible">True</property>

              </object>

            </child>

          </object>

        </child>

        <child>

          <object class="GtkStack" id="stack">

            <signal name="notify::visible-child" handler="visible_child_changed"/>

            <property name="visible">True</property>

          </object>

        </child>