Services refactor

Replace structs of Dep<Service> with OnceServices, so each service has a Services reference

Remove service name => Service map

Flatten Services.rooms

Make reqwest Clients lazy initialized (client service)

src/api/server/event.rs

@@ -16,7 +16,6 @@ pub(crate) async fn get_event_route(
 	body: Ruma<get_event::v1::Request>,
 ) -> Result<get_event::v1::Response> {
 	let event = services
-		.rooms
 		.timeline
 		.get_pdu_json(&body.event_id)
 		.await