Add support for Random.image

Add support for:

[ ] Image API datasource, potentially supporting multiple types of image APIs
[ ] Random.image // returning any UIImage in the universe constrained only to defaults
[ ] Random.image.unconstrained config option to remove any default constraints in compression or format
[ ] RandomImagePreferences struct with configurable options for contentType, format, compression level, sizeLimitation & others
[ ] ImageContentType enum // some specification of the type of content to return, eg: [.profilePhoto, .person, .animal, .nature, .sports]
[ ] ImageFormat // e.g. .gif, .jpg, .png, .hvec
[ ] ImageCompressionLimit // .uncompressed (default), .large, .small, .medium
[ ] ImageSizeLimitation accepting a double representing the maximum file size the image should be compressed to
[ ] Image compression function // already existing in one of our other projects
[ ] Random.image.prefs -- a setter / getter for prefs config & persistence / override
[ ] Random.image.with(_ format: ImageFormat)
[ ] Random.image.compressed(_ to: ImageCompressionLimit)
[ ] Random.image.limited(to fileSize: Double)
[ ] Save any images for a session to the /tmp/ directory
[ ] An option to specify whether or not to save the image permanently to the documents directory
[ ] An option to return all random images currently present in either /tmp/ or /documents

// TODO: evaluate a RandomImage object & properties vs extending UIImage

[ ] Random.image.localUrl returning the location on-device & from the correct bundle
[ ] Random.image.sourceUrl returning the original source
[ ] Random.image.extension returning the extension of the file type as a String for UniversalType indentification use with CoreMobileServices & drag / drop features\
[ ] Random.image.name returning only the source filename excluding extension
- [ ] Random.image.fileName returning the filename including the extension
[ ] Random.image.size.kb returning size in KB
[ ] Random.image.size.mb returning size in MB

GigabiteLabs / random-swift