Support Image Tag

[AlaaAlHallaq]

Steps to reproduce the issue

use any svg file that has an image tag as in the following link:
https://drive.google.com/file/d/11vDTB7wA8-RU0XvrEd6-jHjX_qoUKjQR/view?usp=sharing
note that the image has a shadow witch is an embedded image encoded as base64 in an image tag, the browser will show it, but the library wont.

Please include all relevant code, including all PocketSVG method calls made.
SVGImageView(contentsOf: svgURL)

Specifications

• PocketSVG Version: 2.0
• Xcode Version: 11.6
• iOS/macOS Version: 13.6