on Each
inline fun <T : Any> FetchFlow<T>.onEach(crossinline prefetch: suspend Prefetch.() -> Unit = {}, crossinline fetching: suspend Fetching<T>.() -> Unit = {}, crossinline finished: suspend Finished<T>.() -> Unit = {}): FetchFlow<T>
On each emission, execute a lambda according to Fetch state.
Receiver
The FetchFlow to perform actions on.
Return
The original FetchFlow.