feature: Added uuid validation to string type

[talyssonoc]

Hey @tiagogoncalves89, I fixed what we suggested in the other PR and kept your commit, I hope you don't mind 😄

[wenderjean]

@talyssonoc Do you think we should support both guid and uuid since uuid is an alias for guid function on Joi?

https://github.com/hapijs/joi/blob/v14.3.1/API.md#stringguid---aliases-uuid

[talyssonoc]

@wenderjean I would avoid aliases like that so we don't have a 1-1 map to Joi, the idea is to keep it consistent. But maybe we should use just guid instead of uuid since uuid is the alias and guid is the original, what do you think?

As a follow up PR we could add the possibility to pass the version accepted.

[wenderjean]

I do agree we could use only guid because it automatically leades me to think in a generic version and sure, allow developers to set an specific version in a future feature will be great.

When we merge this one I'm going to open an issue to add version options.