[IMP] web_editor: reposition snippets' thumbs

Part of https://github.com/odoo/odoo/pull/55645
task-2157252

addons/web_editor/static/src/scss/wysiwyg_snippets.scss

@@ -71,10 +71,10 @@ body.editor_enable.editor_has_snippets {
 
         .oe_snippet_thumbnail_img {
             width: 100%;
-            height: 60px;
+            padding-top: 75%;
             background-repeat: no-repeat;
             background-size: contain;
-            background-position: center center;
+            background-position: top center;
             overflow: hidden;
         }