Adds nametemplates for grid editors (#6634)

* Adds nametemplates for grid editors

src/Umbraco.Core/Configuration/Grid/IGridEditorConfig.cs

@@ -6,6 +6,7 @@ namespace Umbraco.Core.Configuration.Grid
     public interface IGridEditorConfig
     {
         string Name { get; }
+        string NameTemplate { get; }
         string Alias { get; }
         string View { get; }
         string Render { get; }

src/Umbraco.Core/PropertyEditors/GridEditor.cs

@@ -18,6 +18,9 @@ namespace Umbraco.Core.PropertyEditors
         [JsonProperty("name", Required = Required.Always)]
         public string Name { get; set; }
 
+        [JsonProperty("nameTemplate")]
+        public string NameTemplate { get; set; }
+
         [JsonProperty("alias", Required = Required.Always)]
         public string Alias { get; set; }