Implement sql trait

[HumanG33k]

I try to work with uuid and https://docs.rs/postgres/latest/postgres/ but i have an issue.

     result = row.get(0); 
                 ^^^ the trait `FromSql<'_>` is not implemented for `Uuid` 

It make sense and it can be fix with creating a trait or using str before but it can be great if it can be native. But it may need sql stuff use by "all" crate.