Fix some editor UI controls visible in Visual Scripting

Source/Editor/GUI/CurveEditor.cs

@@ -16,6 +16,7 @@ namespace FlaxEditor.GUI
     /// <summary>
     /// The base class for <see cref="CurveBase{T}"/> editors. Allows to use generic curve editor without type information at compile-time.
     /// </summary>
+    [HideInEditor]
     public abstract class CurveEditorBase : ContainerControl
     {
         /// <summary>

Source/Editor/GUI/Tabs/Tabs.cs

@@ -11,6 +11,7 @@ namespace FlaxEditor.GUI.Tabs
     /// Represents control which contains collection of <see cref="Tab"/>.
     /// </summary>
     /// <seealso cref="FlaxEngine.GUI.ContainerControl" />
+    [HideInEditor]
     public class Tabs : ContainerControl
     {
         /// <summary>

Source/Editor/GUI/Timeline/GUI/KeyframesEditor.cs

@@ -14,6 +14,7 @@ namespace FlaxEditor.GUI
     /// The generic keyframes animation editor control.
     /// </summary>
     /// <seealso cref="FlaxEngine.GUI.ContainerControl" />
+    [HideInEditor]
     public class KeyframesEditor : ContainerControl
     {
         /// <summary>

Source/Editor/GUI/Timeline/Timeline.cs

@@ -20,6 +20,7 @@ namespace FlaxEditor.GUI.Timeline
     /// The timeline control that contains tracks section and headers. Can be used to create time-based media interface for camera tracks editing, audio mixing and events tracking.
     /// </summary>
     /// <seealso cref="FlaxEngine.GUI.ContainerControl" />
+    [HideInEditor]
     public class Timeline : ContainerControl
     {
         private static readonly KeyValuePair<float, string>[] FPSValues =

Source/Editor/Progress/ProgressHandler.cs

@@ -8,6 +8,7 @@ namespace FlaxEditor.Progress
     /// <summary>
     /// Base class for all editor handlers used to report actions progress to the user.
     /// </summary>
+    [HideInEditor]
     public abstract class ProgressHandler
     {
         /// <summary>