[Web][Restic][Dovecot][Dockerapi] Add restic backups with restore in the UI

- Scheduled, encrypted backups to S3, SFTP, REST or a local folder (new restic-mailcow container)
- Restore of mailboxes and whole domains in the UI, also deleted ones, for admins and domain admins
- Scope set by RESTIC_BACKUP_MODE in mailcow.conf (all, data, config)
- Optional backup before updates (update.sh), helper-scripts/restic.sh for a full restore

data/web/inc/restore.inc.php

@@ -0,0 +1,18 @@
+<?php
+// E-Mail > Restore of admins and domain admins (admin/restore.php, domainadmin/restore.php set $role after protect_route):
+// restores from the snapshots of the backup, also of deleted mailboxes (and domains for admins)
+require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/header.inc.php';
+$_SESSION['return_to'] = $_SERVER['REQUEST_URI'];
+
+$js_minifier->add('/web/js/site/backup.js');
+
+$template = 'restore.twig';
+$template_data = [
+  'acl' => $_SESSION['acl'],
+  'role' => $role,
+  'lang_datatables' => json_encode($lang['datatables']),
+  'backup_configured' => \Mailcow\Backup\BackupModule::fromGlobals()->settings->load()->configured(),
+  'backup_timezone' => getenv('TZ') ?: 'UTC',
+];
+
+require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/footer.inc.php';