Add more SKPicture APIs

[mattleibow]

Description of Change

Adding a few new APIs to help with determining picture and drawable "size" as well as adding the Playback method to SKPicture.

The playback method is different to draw in that draw results in a single "draw the picture" command, but playback effectively replicates what was done to create the picture. There is a small different to the latter in that the picture may optimize/combine commands as well as split commands to best fit into the picture's storage.

Bugs Fixed

• Fixes [FEATURE] Introduce SKPicture.Playback() #2881

API Changes

class SKDrawable {
   public int ApproximateBytesUsed { get; }
}

class SKPicture {
  public int ApproximateBytesUsed { get; }
  public int ApproximateOperationCount { get; }
  public int GetApproximateOperationCount(bool includeNested);
  public void Playback(SKCanvas canvas);
}

Behavioral Changes

None.

Required skia PR

mono/skia#127

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Merged related skia PRs
• Changes adhere to coding standard
• Updated documentation