Update jQuery to 3.3.1. Fixes #3271

Patch by Aditya, with test enhancements from Anthony and Joao at Pivotal.

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/column/static/js/column.js

@@ -287,7 +287,7 @@ define('pgadmin.node.column', [
                   var command = new Backgrid.Command({key: 'Tab', keyCode: 9, which: 9});
                   self.model.trigger('backgrid:edited', self.model, self.column,
                                       command);
-                  next_cell.focus();
+                  next_cell.trigger('focus');
                 }
               }, 20);
             },

web/pgadmin/browser/server_groups/servers/static/js/privilege.js

@@ -381,10 +381,10 @@ define(['sources/gettext', 'underscore', 'jquery', 'backbone', 'backform',
               'header': true,
             }));
         }
-        self.$el.find('input[type=checkbox]').first().focus();
+        self.$el.find('input[type=checkbox]').first().trigger('focus');
         // Since blur event does not bubble we need to explicitly call parent's blur event.
         $(self.$el.find('input[type=checkbox]')).on('blur',function() {
-          self.$el.blur();
+          self.$el.trigger('blur');
         });
 
         // Make row visible in when entering in edit mode.

web/pgadmin/browser/server_groups/servers/static/js/variable.js

@@ -395,7 +395,7 @@ define([
 
           // Add button callback
           if (!(data.disabled || data.canAdd == false)) {
-            $gridBody.find('button.add').first().click(function(e) {
+            $gridBody.find('button.add').first().on('click',(e) => {
               e.preventDefault();
               var canAddRow = _.isFunction(data.canAddRow) ?
                 data.canAddRow.apply(self, [self.model]) : true;