Point, PointF, Size and SizeF: Unary minus operator

### Background and motivation

I propose to add a unary minus operator to the Point, PointF, Size and SizeF structs. It is to improve readability during drawing operations.

### API Proposal

```csharp
namespace System.Drawing;

public struct Point
{
public static Point operator -(Point value) { return new Point(-value.X, -value.Y); }
}

public struct PointF
{
public static PointF operator -(PointF value) { return new PointF(-value.X, -value.Y); }
}

public struct Size
{
public static Size operator -(Size value) { return new Size(-value.Width, -value.Height); }
}

public struct SizeF
{
public static SizeF operator -(SizeF value) { return new SizeF(-value.Width, -value.Height); }
}

```

### API Usage

```csharp
// Translate
graphics.TranslateTransform(
pntLocation
);

// Reverse translate
graphics.TranslateTransform(
-pntLocation
);

```

### Alternative Designs

_No response_

### Risks

_No response_

### Will this feature affect UI controls?

No impact on UI controls.