Add new analytic page: Average time spent into each column

app/Template/analytic/avg_time_columns.php

@@ -0,0 +1,29 @@
+<div class="page-header">
+    <h2><?= t('Average time spent into each column') ?></h2>
+</div>
+
+<?php if (empty($metrics)): ?>
+    <p class="alert"><?= t('Not enough data to show the graph.') ?></p>
+<?php else: ?>
+    <section id="analytic-avg-time-column">
+
+        <div id="chart" data-metrics='<?= json_encode($metrics) ?>' data-label="<?= t('Average time spent') ?>"></div>
+
+        <table class="table-stripped">
+        <tr>
+            <th><?= t('Column') ?></th>
+            <th><?= t('Average time spent') ?></th>
+        </tr>
+        <?php foreach ($metrics as $column): ?>
+        <tr>
+            <td><?= $this->e($column['title']) ?></td>
+            <td><?= $this->dt->duration($column['average']) ?></td>
+        </tr>
+        <?php endforeach ?>
+        </table>
+
+        <p class="alert alert-info">
+            <?= t('This chart show the average time spent into each column for the last %d tasks.', 1000) ?>
+        </p>
+    </section>
+<?php endif ?>