Update docs about validations

Author: KollegOFF

_data/sidebars/flexberry-ember-2_sidebar.yml

@@ -160,9 +160,9 @@ entries:
             url: /efd2_enum.html
             output: web, pdf
 
-          - title: Model validation
-            title_ru: Валидация модели
-            url: /efd2_model-validation.html
+          - title: Data validation
+            title_ru: Валидация данных
+            url: /efd3_validations.html
             output: web, pdf
 
           - title: Date and time validation

_data/sidebars/flexberry-ember-3_sidebar.yml

@@ -51,9 +51,9 @@ entries:
             url: /efd3_query-language.html
             output: web, pdf
 
-          - title: Model validation
-            title_ru: Валидация моделей
-            url: /efd3_model-validation.html
+          - title: Data validation
+            title_ru: Валидация данных
+            url: /efd3_validations.html
             output: web, pdf
 
       - title: Components