Besides a connector and pool, the Client from 0.14.x did many small things that should be decomposed into pieces in hyper-util, so users can choose to compose the parts they want.

• Create a SetHost service layer (could also fit in tower-http) (0.14.x code)
• Create a Http1RequestTarget service layer (0.14.x code)
• Create a DelayedRelease service layer (0.14.x code)
• Create an AutoConnection which can wrap HTTP/1 and HTTP/2 (and eventually 3) connections