Add a macro for generating wrapper types

[elichai]

A lot of time you use multiple different UUIDs for different purposes in the same app, in those scenarios you want to wrap the Uuid type with your own, you start with a slim API and slowly it grows and grows for each wrapper type.
if the library could export a macro_rules macro that creates wrapper types with all the API included that could be pretty cool.
(honestly, it is starting to feel like this should be a language feature :) )

Would love to hear other opinions :) (if you're supportive of this I can find some time to draft a PR)