[Epic] Image and ImageSource refactoring

[MartinZikmund]

What would you like to be added

Image and ImageSource have a significant technical debt built up from many incremental updates across all different targets. To allow for easier maintenance going forward, we need to refactor the code for better code-sharing, and more clear load/open/measure/arrange lifecycle.

In addition, we should incorporate a reliable cross-platform image caching approach, ideally reusing the logic that WinUI applies internally, so that we avoid wasting resources when large amount of image data is loaded sequentially

Why is this needed

Better maintenance and reliability.