Add Image Dialog with Zoom and Dismiss Functionality in EPUB

[nageshwararao1988]

This PR introduces a feature in the EPUB viewer where tapping on an image opens it in a modal dialog with zoom functionality. The following updates are included:

Image Modal Dialog: Images can now be tapped to open in a dialog.
Zoom Support: Users can zoom in and out of the displayed image for better visibility.
Dismiss Button: A "Dismiss" button is provided in the top-right corner of the dialog, allowing users to close it and return to the main content.
User Experience Improvements: Ensures a seamless interaction without interfering with the reading experience.
This feature enhances accessibility and usability for users who want to examine images closely within the EPUB content.

[mickael-menu]

Thank you for opening a PR @nageshwararao1988.

Unfortunately, the implementation does not fit the principles of our toolkit as you implemented your specific use case instead of a general solution that would work with other apps.

For example:

• What if an app wants to do something different than zooming the image when tapping on it? Or zoom the image when doing a long tap or a pinch instead (if we implement support for these gestures in the future).
• The animation and the zooming UI are hard-coded in the toolkit, but should be customizable by the app. An integrator could want a different way to close the zooming view, or display the alt text of the image underneath. A core principle of the toolkit is to let the application provide its own UX.
• The Dismiss button is hard-coded and cannot be translated.

A good way to implement this feature in Readium would be:

• Adding information about the target element in the TapEvent sent to the host app, including the resource href if it's an image, and the position rect in the navigator view.
• Implementing the zooming UI in the test app when receiving a TapEvent on an image, by getting the content of the image using its href, and for example implementing a zooming animation using the position rect in the TapEvent.