Add test coverage for StandardOleMarshalObject

[ericstj]

See dotnet/corefx#32491

We should add test coverage for this newly ported type.

@luqunl do you know of a trick to route a call through COM using purely managed code (eg: an RCW(CCW(managedobject)))

If we can do that, then I can imagine we could just call a COM-exposed method on the StandardOleMarshalObject derived type from a different thread and verify that it runs on the main thread.

/cc @Anipik

[luqunl]

Yes, You can use ICustomQueryInterface to trick interop --- the StandardOleMarshalObject derived type should implements ICustomQueryInterface to tell interop this is a native object.

``
class MyStandardOleMarshalObject : StandardOleMarshalObject, ICustomQueryInterface
{

    static readonly Guid IID_IMarshal = new Guid("00000003-0000-0000-C000-000000000046");
    static readonly Guid IID_IManagedObject = new Guid("C3FCC19E-A970-11d2-8B5A-00A0C9B7C9C4");

    CustomQueryInterfaceResult ICustomQueryInterface.GetInterface(ref Guid iid, out IntPtr ppv)
    {
        if (iid == IID_IMarshal ||
            iid == IID_IManagedObject
            )
        {
            ppv = IntPtr.Zero;
            return CustomQueryInterfaceResult.Failed;
        }

        ppv = IntPtr.Zero;
        return CustomQueryInterfaceResult.NotHandled;
    }

``

[ericstj]

Duplicate of https://github.com/dotnet/corefx/issues/30952