Added generic typing to layer properties and keyframes

Restructured the way property input VMs are created

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

@@ -0,0 +1,49 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+
+namespace Artemis.Core.Models.Profile.LayerProperties
+{
+    public class LayerProperty<T> : BaseLayerProperty
+    {
+        public LayerProperty(Layer layer, BaseLayerProperty parent, string id, string name, string description) : base(layer, parent, id, name, description, typeof(T))
+        {
+        }
+
+        public T Value
+        {
+            get => (T) BaseValue;
+            set => BaseValue = value;
+        }
+
+        /// <summary>
+        ///     A list of keyframes defining different values of the property in time, this list contains the strongly typed <see cref="Keyframe{T}"/>
+        /// </summary>
+        public ReadOnlyCollection<Keyframe<T>> Keyframes => BaseKeyframes.Cast<Keyframe<T>>().ToList().AsReadOnly();
+
+        /// <summary>
+        ///     Adds a keyframe to the property.
+        /// </summary>
+        /// <param name="keyframe">The keyframe to remove</param>
+        public void AddKeyframe(Keyframe<T> keyframe)
+        {
+            BaseKeyframes.Add(keyframe);
+        }
+
+        /// <summary>
+        ///     Removes a keyframe from the property.
+        /// </summary>
+        /// <param name="keyframe">The keyframe to remove</param>
+        public void RemoveKeyframe(Keyframe<T> keyframe)
+        {
+            BaseKeyframes.Remove(keyframe);
+        }
+
+        /// <summary>
+        ///     Removes all keyframes from the property.
+        /// </summary>
+        public void ClearKeyframes()
+        {
+            BaseKeyframes.Clear();
+        }
+    }
+}