Schema Cache Improvement 2 (#5616)

* schema hasClass improvement

* create object improvement

* destroy object

* update object

* hasClass test rewrite

* more tests

* improve signing up users

spec/Schema.spec.js

@@ -929,6 +929,7 @@ describe('SchemaController', () => {
       .then(schema => {
         return schema
           .addClassIfNotExists('NewClass', {})
+          .then(() => schema.reloadData({ clearCache: true }))
           .then(() => {
             schema
               .hasClass('NewClass')