refactoring: setup wizard pages with simple architecture.

server/src/system/models/Tenant.js

@@ -17,6 +17,20 @@ export default class Tenant extends BaseModel {
     return ['createdAt', 'updatedAt'];
   }
 
+  /**
+   * Virtual attributes.
+   */
+  static get virtualAttributes() {
+    return ['isReady'];
+  }
+
+  /**
+   * Tenant is ready.
+   */
+  get isReady() {
+    return !!(this.initializedAt && this.seededAt);
+  }
+
   /**
    * Query modifiers.
    */