MDL-68563 filter_emoticon: enable filter uppon install

Every major system that people use these days turns smiles into emoticons automatically.

This filter was turned off by default a decade ago because of performance concerns
that do not apply any more, specially on fresh new installations.

In order to improve users experience on text editing features the emoticon filter
will be now enabled by default in new installations.

filter/emoticon/db/install.php

@@ -0,0 +1,32 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Emoticon filter post install hook.
+ *
+ * @package    filter_emoticon
+ * @copyright  2020 Simey Lameze <simey@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+function xmldb_filter_emoticon_install() {
+    global $CFG;
+    require_once($CFG->libdir . "/filterlib.php");
+
+    filter_set_global_state('emoticon', TEXTFILTER_ON, 0);
+}