Moved more abstractions of models

src/Umbraco.Abstractions/Models/StylesheetProperty.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Runtime.Serialization;
+using Umbraco.Core.Models.Entities;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Represents a Stylesheet Property
+    /// </summary>
+    /// <remarks>
+    /// Properties are always formatted to have a single selector, so it can be used in the backoffice
+    /// </remarks>
+    [Serializable]
+    [DataContract(IsReference = true)]
+    public class StylesheetProperty : BeingDirtyBase, IValueObject
+    {
+        private string _alias;
+        private string _value;
+
+        public StylesheetProperty(string name, string @alias, string value)
+        {
+            Name = name;
+            _alias = alias;
+            _value = value;
+        }
+
+        /// <summary>
+        /// The CSS rule name that can be used by Umbraco in the back office
+        /// </summary>
+        public string Name { get; private set; }
+
+        /// <summary>
+        /// This is the CSS Selector
+        /// </summary>
+        public string Alias
+        {
+            get => _alias;
+            set => SetPropertyValueAndDetectChanges(value, ref _alias, nameof(Alias));
+        }
+
+        /// <summary>
+        /// The CSS value for the selector
+        /// </summary>
+        public string Value
+        {
+            get => _value;
+            set => SetPropertyValueAndDetectChanges(value, ref _value, nameof(Value));
+        }
+
+    }
+}