[FIX] website_slides: correctly return deferred when calling slide routes in fullscreen

I promise to fix all deferred. Huk huk huk.

Commit linked to task ID 1941250 and PR #31584.

addons/website_slides/controllers/main.py

@@ -559,11 +559,13 @@ class WebsiteSlides(WebsiteProfile):
     # SLIDE.SLIDE UTILS
     # --------------------------------------------------
 
-    @http.route('/slide/html_content/get', type="json", auth="public", website=True)
+    @http.route('/slides/slide/get_html_content', type="json", auth="public", website=True)
     def get_html_content(self, slide_id):
-        slide = request.env['slide.slide'].browse(slide_id)
+        fetch_res = self._fetch_slide(slide_id)
+        if fetch_res.get('error'):
+            return fetch_res
         return {
-            'html_content': slide.html_content
+            'html_content': fetch_res['slide'].html_content
         }
 
     @http.route('/slides/slide/<model("slide.slide"):slide>/set_completed', website=True, type="http", auth="user")

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

@@ -201,7 +201,7 @@ odoo.define('website_slides.fullscreen', function (require) {
          */
         _fetchQuiz: function (){
             var self = this;
-            self._rpc({
+            return self._rpc({
                 route:"/slide/quiz/get",
                 params: {
                     'slide_id': self.slide.id
@@ -215,8 +215,8 @@ odoo.define('website_slides.fullscreen', function (require) {
         },
         _fetchHtmlContent: function (){
             var self = this;
-            self._rpc({
-                route:"/slide/html_content/get",
+            return self._rpc({
+                route: 'slides/slide/get_html_content',
                 params: {
                     'slide_id': self.slide.id
                 }
@@ -234,7 +234,7 @@ odoo.define('website_slides.fullscreen', function (require) {
          */
         _setSlideStateAsDone: function (){
             var self = this;
-            self._rpc({
+            return self._rpc({
                 route: '/slides/slide/set_completed',
                 params: {
                     slide_id: self.slide.id,