[FIX] rating: fix image computation and display

Currently if we try to display image of a rating having a different value of
0/1/5/10 there is an infinite loading. Indeed images for rating are limited
to those values.

In this commit we fix that by computing a rounded value to find the closest
image.

Text display in form view is also centered for better wow onboarding back 2
basics demo usability fiximp effect.

addons/rating/models/rating.py

@@ -67,9 +67,18 @@ class Rating(models.Model):
 
     @api.depends('rating')
     def _compute_rating_image(self):
+        # Due to some new widgets, we may have ratings different from 0/1/5/10 (e.g. slide.channel review)
+        # Let us have some custom rounding while finding a better solution for images.
         for rating in self:
+            rating_for_img = 0
+            if rating.rating >= 8:
+                rating_for_img = 10
+            elif rating > 3:
+                rating_for_img = 5
+            elif rating.rating >= 1:
+                rating_for_img = 1
             try:
-                image_path = get_resource_path('rating', 'static/src/img', 'rating_%s.png' % (int(rating.rating),))
+                image_path = get_resource_path('rating', 'static/src/img', 'rating_%s.png' % rating_for_img)
                 rating.rating_image = base64.b64encode(open(image_path, 'rb').read())
             except (IOError, OSError):
                 rating.rating_image = False

addons/rating/views/rating_view.xml

@@ -42,7 +42,7 @@
                             <group>
                                 <div colspan="2" class="text-center">
                                     <field name="rating_image" widget='image'/>
-                                    <div class="mt4 text-left">
+                                    <div class="mt4">
                                         <strong><field name="rating_text"/></strong>
                                     </div>
                                 </div>