Consider `system` feature

[Yota Hamada]

The system as a "foreach-system" function feature in Bevy looks interesting.
I am wondering if there's way to achieve the same in donburi using Generics.
This way the user doesn't have to get components directly using query.EachEntity() but it will be suppilied to the system function automatically, which is nice.

[Yota Hamada]

One idea:

func collisionSystem(query1, query2 *donburi.Query) {
  // ...
}

world.AddSystem(query1, query2, collisionSystem)

[Yota Hamada]

Draw system:

func playerDrawer(screen *ebiten.Image, query *donburi.Query) {
  // ...
}

world.AddDrawerSystem(query, playerDrawer)
world.Draw(screen)

[Yota Hamada]

Implemented as ECS package