[REF] web_editor: review some dropzone code

- Remove useless code
- Make searching for the nearest dropzone more efficient

addons/web_editor/static/src/js/editor/snippets.editor.js

@@ -1239,10 +1239,10 @@ var SnippetsMenu = Widget.extend({
             stop: function (ev, ui) {
                 $toInsert.removeClass('oe_snippet_body');
 
-                if (! dropped && self.$editable.find('.oe_drop_zone') && ui.position.top > 3 && ui.position.left + 50 > self.$el.outerWidth()) {
-                    var el = self.$editable.find('.oe_drop_zone').nearest({x: ui.position.left, y: ui.position.top}).first();
-                    if (el.length) {
-                        el.after($toInsert);
+                if (!dropped && ui.position.top > 3 && ui.position.left + 50 > self.$el.outerWidth()) {
+                    var $el = $.nearest({x: ui.position.left, y: ui.position.top}, '.oe_drop_zone').first();
+                    if ($el.length) {
+                        $el.after($toInsert);
                         dropped = true;
                     }
                 }

addons/web_editor/static/src/scss/web_editor.ui.scss

@@ -270,8 +270,6 @@ html[lang] > body.editor_enable [data-oe-translation-state] {
         height: $o-we-dropzone-size;
         margin: (-$o-we-dropzone-size/2) 0;
 
-        transition: margin 400ms linear 0s;
-
         &:after {
             content: "";
             display: block;