added checks for content_item_id on field_item to avoid uniqueness validation on update
added checks for content_item_id on field_item to avoid uniqueness validation on update

cortex-cms/cortex-plugins-core,cortex-cms/cortex-field_types-core,cortex-cms/cortex-field_types-core,cortex-cms/cortex-plugins-core,cortex-cms/cortex-plugins-core,cortex-cms/cortex-field_types-core