Add a Task based dispatch mechanism

[chouzar]

Dispatching to subjects in the registry should be done in independent tasks.

[chouzar]

Added a dispatch in ea8990e it is very fragile.

• Dispatch should be ran in another process:
  • This process may use a pool, rather than a queue to spawn tasks.
  • Should we guarantee order of dispatches/tasks?

[chouzar]

Had to re-think how to dispatch tasks to multiple subjects in the registry, this signature should be a good starting point:

/// Applies a callback over a group.
/// 
/// ## Example
/// 
/// ```gleam
/// chip.dispatch_group(registry, Pets, fn(subject) { 
///   process.send(subject, message)
/// })
/// ```
pub fn dispatch(
  registry: Registry(msg, group),
  group: group,
  callback: fn(process.Subject(msg)) -> x,
) -> Nil {
  todo
}

The previous implementation can be found at v0.9.0.