Support leaving a struct out of the output

Ticket from Codeberg

For cases where there is a base class, the base class might never actually be used and just serve as a placeholder for common attributes to be shared.

#[inheriters(no_output=true)]
struct Base {
  base_attr1: u8,
}

#[inherit(Base)]
struct Child {
  child_attr1: u8,
}

should lead to Base being ignored in the output

struct Child {
  base_attr1: u8,
  child_attr1: u8
}