Breaking Changes:
* `System.Drawing.Common` is dropped and `SixLabors.ImageSharp` is introduced.
* uses of `NativeImage.CreateFromBitmap(bitmap, options);` is no longer supported, will cause failed builds.
Unexpected Behaviors:
* uses ToDataUrl will always create png data urls, unexpected output may happen for those that manipulate this output expecting a different data url format.
Obsoletions:
* `CreateFromBitmapOptions` & `CreateFromBufferOptions` have been consolidated into `CreateOptions`. Implicit conversions added to ease transition.
* `ToBitmapOptions`, `ToDataUrlOptions`, `ToPngOptions` & `BitmapOptions` have been consolidated into `ImageOptions`. Implicit conversions added to ease transition.
