Nuke 12.0 (Beta 4)

• Remove the convenience LazyImage(url:content:placeholder:) init method that doesn't offer much compared to the main init and remove public _LazyImageContents
• Fix an issue where if you change the LazyImage's processors or priority without also changing the image source, the image wasn't being reloaded
• Remove some of the typealises from NukeUI
• Remove the deprecated APIs in NukeUI
• Add missing scale parameter to init with content
• ImageDecoder now defaults to scale 1 for images
• Remove scale parameter from LazyImage init: it's available via ImageRequest userInfo