Better local context management API

[Paul S.]

local.named("context1").from(defs: ModuleDef)

(local: LocalContext) =>

val producer: Producer = local.provide(DIKey.get[Import] -> value, ...)
producer.run / producer.produceFX / ....

The plan produced by the binding must be done in a context inherited from the outer injector.

[Kai]

Would probably need to declare 'context' components for the compile checker:

  declareHole[Ctx[F]]