Feature request: support for generic enums?

Hi!

I think it would be nice to be able to support something like

#[enum_delegate::implement(Trait)]
pub enum EnumWithGeneric<T> where T: Foo {
  Variant1(SomeStructThatImplsTrait<T>),
  Variant2(SomeOtherStructThatImplsTrait<T>),
  ...
}

It seems like this could work by "just" adding the generic parameters to the impl<> and where blocks of the generated impl Trait for EnumWithGeneric block. Do we think this would be desirable as a feature to support? If so, I could work on adding this.