Support aliased and inlined struct type enum variants

[worstell]

both of the below will be supported ways of declaring struct type enum variants:

type TypeEnum interface {
   typeenum()
}

type Inlined struct {
}
func (Inlined) typeenum()

type Aliased Underlying {
}
func (Aliased) typeenum()

type Underlying struct {
}

producing the following schema:

enum TypeEnum {
   Inlined foo.Inlined
   Aliased foo.Underlying
}

if the struct is inlined, we will use its name as both the variant name and the type name. right now, we're only supporting the inlined case correctly