Fix #3030: Add upload the sqlite database feature

app/Template/config/upload_db.php

@@ -0,0 +1,18 @@
+<div class="page-header">
+    <h2><?= t('Upload the Sqlite database') ?></h2>
+</div>
+
+<div class="alert">
+    <ul>
+        <li><?= t('You can upload Gzip compressed Sqlite database you previously downloaded') ?></li>
+    </ul>
+</div>
+
+<form action="<?= $this->url->href('ConfigController', 'uploadDbSave') ?>" method="post" enctype="multipart/form-data">
+    <?= $this->form->csrf() ?>
+
+    <?= $this->form->label(t('Database file'), 'file') ?>
+    <?= $this->form->file('file') ?>
+
+    <?= $this->modal->submitButtons(array('submitLabel' => t('Upload'))) ?>
+</form>