[2.0] Improved Image Handling

[EricBAndrews]

Improve how we handle images across the board:

• Use Nuke ImageProcessors to perform resizing upstream
• Investigate fetching full-size and resizing to all required resolutions using upstream image requests (might require custom image processor)
• Investigate lazy loading if above results in excessive network usage
• Refactor DynamicImageView to use LazyImage (we don't need the Image(uiImage) construction because DynamicImageView never appears in animation/problem views)
• Use full-size image for .saveImage