Added layer properties to core and hooked it up with the UI

Implemented timeline caret scrolling logic
Added special treeview style for the layer properties tree

src/Artemis.Core/Models/Profile/LayerProperty.cs

@@ -1,16 +1,23 @@
 using System;
 using System.Collections.Generic;
+using Artemis.Core.Exceptions;
 
 namespace Artemis.Core.Models.Profile
 {
     public class LayerProperty
     {
-        internal LayerProperty(Layer layer, LayerProperty parent)
+        private object _baseValue;
+
+        internal LayerProperty(Layer layer, LayerProperty parent, string name, string description, Type type)
         {
             Layer = layer;
             Parent = parent;
+            Name = name;
+            Description = description;
+            Type = type;
 
             Children = new List<LayerProperty>();
+            Keyframes = new List<Keyframe>();
         }
 
         public Layer Layer { get; }
@@ -20,7 +27,23 @@ namespace Artemis.Core.Models.Profile
         public string Name { get; set; }
         public string Description { get; set; }
         public Type Type { get; set; }
-        public object BaseValue { get; set; }
+
+        public object BaseValue
+        {
+            get => _baseValue;
+            set
+            {
+                if (value != null && value.GetType() != Type)
+                    throw new ArtemisCoreException($"Cannot set value of type {value.GetType()} on property {Name}, expected type is {Type}.");
+                _baseValue = value;
+            }
+        }
+
         public List<Keyframe> Keyframes { get; set; }
+
+        public void ApplyToEntity()
+        {
+            // Big o' TODO
+        }
     }
 }