Remove deprecated controls #2091
Description
Problem description:
The following types have been deprecated in .NET Framework:
- https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/DataGrid.cs (e.g. deprecation warning)
- https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/Menu.cs
- https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/MenuItem.cs
- https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/MainMenu.cs
- https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/ContextMenu.cs
However this fact was overlooked during the migration, and the types were brought into .NET Core 3.0.
Expected behavior:
The types are not available to consumers via intellisense.
