Add Funnel.Caches

  * Supervises all `Funnel.Transistor.Caches`
  * `Caches` can be started without any `Transistor`

Signed-off-by: chatgris <jboyer@af83.com>
Do not start transistor on notification

`Funnel.Transistor` are only started when a client connects to the
stream.

Signed-off-by: chatgris <jboyer@af83.com>
Fix Cache's id

Signed-off-by: chatgris <jboyer@af83.com>