Added constants for Property Editor Groups

src/Umbraco.Core/Constants-PropertyEditors.cs

@@ -203,6 +203,24 @@ namespace Umbraco.Core
                 /// <remarks>Must be a valid <see cref="ValueTypes"/> value.</remarks>
                 public const string DataValueType = "umbracoDataValueType";
             }
+
+            /// <summary>
+            /// Defines Umbraco's built-in property editor groups.
+            /// </summary>
+            public static class Groups
+            {
+                public const string Common = "Common";
+
+                public const string Lists = "Lists";
+
+                public const string Media = "Media";
+
+                public const string People = "People";
+
+                public const string Pickers = "Pickers";
+
+                public const string RichContent = "Rich Content";
+            }
         }
     }
 }

src/Umbraco.Core/PropertyEditors/DataEditor.cs

@@ -30,7 +30,7 @@ namespace Umbraco.Core.PropertyEditors
             // defaults
             Type = type;
             Icon = Constants.Icons.PropertyEditor;
-            Group = "common";
+            Group = Constants.PropertyEditors.Groups.Common;
 
             // assign properties based on the attribute, if it is found
             Attribute = GetType().GetCustomAttribute<DataEditorAttribute>(false);

src/Umbraco.Core/PropertyEditors/DataEditorAttribute.cs

@@ -121,7 +121,7 @@ namespace Umbraco.Core.PropertyEditors
         /// Gets or sets an optional group.
         /// </summary>
         /// <remarks>The group can be used for example to group the editors by category.</remarks>
-        public string Group { get; set; } = "common";
+        public string Group { get; set; } = Constants.PropertyEditors.Groups.Common;
 
         /// <summary>
         /// Gets or sets a value indicating whether the value editor is deprecated.

src/Umbraco.Core/PropertyEditors/LabelPropertyEditor.cs

@@ -5,7 +5,11 @@ namespace Umbraco.Core.PropertyEditors
     /// <summary>
     /// Represents a property editor for label properties.
     /// </summary>
-    [DataEditor(Constants.PropertyEditors.Aliases.Label, "Label", "readonlyvalue", Icon = "icon-readonly")]
+    [DataEditor(
+        Constants.PropertyEditors.Aliases.Label,
+        "Label",
+        "readonlyvalue",
+        Icon = "icon-readonly")]
     public class LabelPropertyEditor : DataEditor
     {
         /// <summary>