add apply button to observation settings tab

             <zorder>twistCheckBox_2</zorder>

            </widget>

           </item>

           <item row="0" column="0" rowspan="2">

           <item row="2" column="1">

            <widget class="QPushButton" name="pushButton">

             <property name="text">

              <string>Apply Settings to Selected Images</string>

             </property>

            </widget>

           </item>

           <item row="0" column="0" rowspan="3">

            <widget class="QTreeView" name="treeView">

             <property name="editTriggers">

              <set>QAbstractItemView::NoEditTriggers</set>