Add generic properties as group

src/Umbraco.Web/Models/Mapping/PropertyTypeGroupMapper.cs

@@ -146,6 +146,7 @@ namespace Umbraco.Web.Models.Mapping
                 var genericTab = new PropertyGroupDisplay<TPropertyType>
                 {
                     Id = PropertyGroupBasic.GenericPropertiesGroupId,
+                    Level = 1,
                     Name = "Generic properties",
                     ContentTypeId = source.Id,
                     SortOrder = 999,

src/Umbraco.Web/Models/Mapping/TabsAndPropertiesMapper.cs

@@ -58,6 +58,7 @@ namespace Umbraco.Web.Models.Mapping
             tabs.Add(new Tab<ContentPropertyDisplay>
             {
                 Id = 0,
+                Level = 1,
                 Label = LocalizedTextService.Localize("general/properties"),
                 Alias = "Generic properties",
                 Properties = genericproperties