Generic Iid component

[Trouv]

Many types in LDtk have an Iid, and I think it's becoming increasingly useful to create components storing these values on the corresponding entities. This is being done for LevelIid and EntityIid currently. However, these two implementations are pretty different, when they could be pretty much exactly the same type with a slightly different context.

Instead we could have a generic LdtkIid<> component and contextualize it with a generic parameter. Something like...

trait LdtkInstance {}
impl LdtkInstance for EntityInstance {}
impl LdtkInstance for Level {}

#[derive(Component)]
struct LdtkIid<I>
    where I: LdtkInstance
{
    iid: String,
    phantom: PhantomData<I>,
}

type LevelIid = LdtkIid<Level>;
type EntityIid = LdtkIid<EntityInstance>;

This would reduce repeated code and make it easier to add other Iid components in the future