Intersection Merging

Changed

• Removed Key type
• Add a Uuid type
• Make type value a title-cased string
• Rename Accepted and Rejected to Whitelist and Blacklist
• Add _isType structural type check (for selecting branches without validation)
• Merge the results of intersection types together
• Return the result of validation instead of input value (now intersections properly intersect results)
• Replaced object patterns with propertyTypes