Fix bindable elements UxmlFactory issue.

Author: ChebanovDD

src/UnityMvvmToolkit.UnityPackage/Assets/Plugins/UnityMvvmToolkit/Runtime/UITK/BindableUIElements/Uxmls/BindableButton.Uxml.cs

@@ -7,6 +7,10 @@ partial class BindableButton
     {
         public string Command { get; private set; }
 
+        public new class UxmlFactory : UxmlFactory<BindableButton, UxmlTraits>
+        {
+        }
+
 #if UNITY_2023_2_OR_NEWER
         [System.Serializable]
         public new class UxmlSerializedData : BaseButton.UxmlSerializedData
@@ -23,10 +27,6 @@ public override void Deserialize(object visualElement)
                 visualElement.As<BindableButton>().Command = Command;
             }
         }
-
-        public new class UxmlFactory : UxmlFactory<BindableButton, UxmlTraits>
-        {
-        }
 #else
         public new class UxmlTraits : BaseButton.UxmlTraits
         {

src/UnityMvvmToolkit.UnityPackage/Assets/Plugins/UnityMvvmToolkit/Runtime/UITK/BindableUIElements/Uxmls/BindableLabel.Uxml.cs

@@ -7,6 +7,10 @@ partial class BindableLabel
     {
         public string BindingTextPath { get; private set; }
 
+        public new class UxmlFactory : UxmlFactory<BindableLabel, UxmlTraits>
+        {
+        }
+
 #if UNITY_2023_2_OR_NEWER
         [System.Serializable]
         public new class UxmlSerializedData : Label.UxmlSerializedData
@@ -23,10 +27,6 @@ public override void Deserialize(object visualElement)
                 visualElement.As<BindableLabel>().BindingTextPath = BindingTextPath;
             }
         }
-
-        public new class UxmlFactory : UxmlFactory<BindableLabel, UxmlTraits>
-        {
-        }
 #else
         public new class UxmlTraits : Label.UxmlTraits
         {

src/UnityMvvmToolkit.UnityPackage/Assets/Plugins/UnityMvvmToolkit/Runtime/UITK/BindableUIElements/Uxmls/BindableTextField.Uxml.cs

@@ -7,6 +7,10 @@ partial class BindableTextField
     {
         public string BindingValuePath { get; private set; }
 
+        public new class UxmlFactory : UxmlFactory<BindableTextField, UxmlTraits>
+        {
+        }
+
 #if UNITY_2023_2_OR_NEWER
         [System.Serializable]
         public new class UxmlSerializedData : TextField.UxmlSerializedData
@@ -23,10 +27,6 @@ public override void Deserialize(object visualElement)
                 visualElement.As<BindableTextField>().BindingValuePath = BindingValuePath;
             }
         }
-
-        public new class UxmlFactory : UxmlFactory<BindableTextField, UxmlTraits>
-        {
-        }
 #else
         public new class UxmlTraits : TextField.UxmlTraits
         {