Support UUID as field type

[Nokel81]

I have tried to use UUID as a field type and it just gets ignored (which is not very useful if it is your primary key). I have checked the fields.go file and it seems to be ignored because it is a type that doesn't have a //gen:qs comment on top of it.

However, with some more testing it seems that the root problem is more about the handling of fixed sized arrays as field types. I can understand that this is normally a problem since it doesn't map to SQL style databases very well. However, fixed byte arrays are generally supported.