Add `updateOrDelete` to immutable Maps

[Lasering]

def updateOrDelete[V1 >: V](key: K)(updateOrDelete: Option[V1]): Map[K, V1] =
  updateOrDelete match {
    case None => this.removed(key)
    case Some(value) => this.updated(key, value)
  }

[BalmungSan]

You can already do this using updatedWith like:

map.updatedWith(key)(_ => updateOrDelete)