Support derivation for self-based type classes

[halotukozak]

Self-based type classes, e.g.

trait TC:
  type Self
  def apply(): Self

given Int is TC = () => 42

doesn't support derivation

object TC:
  def derived[X]: X is TC = ???

  case class C() derives TC

error: type TC in derives clause of C has no type parameters

It can be achieved via

given C is TC = TC.derived

But imo, to make modularity changes comprehensive, derivation should be supported (similarly to the context bounds)