Rework ImageRequest

[kean]

Changes

• Move advanced options into separate ImageRequestOptions struct
• Remove the entire zoo of processing API, leaves a single one - processors: [ImageProcessing]
• Initializers now accept every single option that request might have

Examples

Settings processor:

let request = ImageRequest(url: URL(string: "http://..."), processors: [
    ImageProcessor.Resize(size: CGSize(width: 44, height: 44))
])

Setting priority:

let request = ImageRequest(url: URL(string: "http://..."), priority: .high)

Setting everything:

let request = ImageRequest(
    url: URL(string: "http://..."),
    processors: [
        ImageProcessor.Resize(size: CGSize(width: 44, height: 44), crop: true),
        ImageProcessor.RoundedCorners(radius: 16)
    ],
    priority: .high,
    options: .init(
        memoryCacheOptions: .init(
            isReadAllowed: false,
            isWriteAllowed: false
        ),
        cacheKey: "1",
        loadKey: "2",
        userInfo: "hello"
    )
)