[FIX] website_slides: don't show sidebar, mobile

On mobile, don't show automatically the sidebar in order to
avoid covering the lesson's content.
The user will have to click on the toggle button to open it.

part of: https://github.com/odoo/odoo/pull/34151

addons/website_slides/static/src/js/slides_course_fullscreen_player.js

@@ -5,6 +5,7 @@ odoo.define('website_slides.fullscreen', function (require) {
     var sAnimations = require('website.content.snippets.animation');
     var Widget = require('web.Widget');
     var core = require('web.core');
+    var config = require('web.config');
     var QWeb = core.qweb;
 
     var session = require('web.session');
@@ -321,6 +322,9 @@ odoo.define('website_slides.fullscreen', function (require) {
         start: function (){
             var self = this;
             this.on('change:slide', this, this._onChangeSlide);
+            if  (config.device.size_class > config.device.SIZES.MD) {
+                this._toggleSidebar();
+            }
             return this._super.apply(this, arguments).then(function () {
                 self._onChangeSlide(); // trigger manually once DOM ready, since slide content is not rendered server side
             });
@@ -540,12 +544,20 @@ odoo.define('website_slides.fullscreen', function (require) {
             this.sidebar.goNext();
         },
         /**
-         * Show or Hide the sidebar
+         * Called when the sidebar toggle is clicked -> toggles the sidebar visibility.
          *
          * @private
          */
         _onClickToggleSidebar: function (ev){
             ev.preventDefault();
+            this._toggleSidebar();
+        },
+        /**
+         * Toggles sidebar visibility.
+         *
+         * @private
+         */
+        _toggleSidebar: function () {
             this.$('.o_wslides_fs_sidebar').toggleClass('o_wslides_fs_sidebar_hidden');
             this.$('.o_wslides_fs_toggle_sidebar').toggleClass('active');
         },

addons/website_slides/views/website_slides_templates_lesson_fullscreen.xml

@@ -8,7 +8,7 @@
 
             <div class="o_wslides_slide_fs_header d-flex flex-shrink-0 text-white">
                 <div class="d-flex">
-                    <a class="o_wslides_fs_toggle_sidebar d-flex align-items-center px-3 active" href="#" title="Lessons">
+                    <a class="o_wslides_fs_toggle_sidebar d-flex align-items-center px-3" href="#" title="Lessons">
                         <i class="fa fa-bars"/><span class="d-none d-md-inline-block ml-1">Lessons</span>
                     </a>
                     <a class="o_wslides_fs_review d-flex align-items-center px-3" t-att-href="slide.channel_id.website_url" title="Reviews" t-if="slide.channel_id.allow_comment">
@@ -28,7 +28,7 @@
             <div class="o_wslides_fs_container d-flex position-relative overflow-hidden flex-grow-1">
                 <div class="o_wslides_fs_content align-items-stretch justify-content-center d-flex flex-grow-1 order-2"></div>
 
-                <div class="o_wslides_fs_sidebar text-white flex-shrink-0 order-1">
+                <div class="o_wslides_fs_sidebar o_wslides_fs_sidebar_hidden text-white flex-shrink-0 order-1">
                     <div class="o_wslides_fs_sidebar_content d-flex flex-column px-3 pt-3 h-100">
                         <div class="o_wslides_fs_sidebar_header mb-3">
                             <a class="h5 d-block mb-1" t-attf-href="/slides/#{slug(slide.channel_id)}">